Difficulty Level: 3 Difficulty scale: Adding air to your tires is level one Rebuilding a BMW Motor is level ten
This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your BMW 3 Series. The book contains 272 pages of full color projects detailing everything from performance mods to timing the camshafts. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any 3 Series owner's collection. The book was released in August 2006, and is available for ordering now. See The Official Book Website for more details.
One often neglected task on many cars is the maintenance of the cooling system. In general, BMW recommends that you flush and clean out your cooling system once every 36 months, or approximately every three years. I like to perform this task on my own cars about once a year, or if I let it slip, once every two years. The reason for this is that old, exhausted coolant can actually cause irreversible damage to your engine components - I found this out firsthand when I recently replaced the head gasket on my '93 325is. The previous owner didn't look like he had changed the fluid once in the past ten years. As a result, there were many parts of the engine that were corroded and showing severe signs of wear.
A properly maintained cooling system must have a few things in order: adequate supply of coolant, a radiator that acts as a heat exchanger with the outside air, a fan or air flow source, a water pump to keep the coolant circulating, and a thermostat to regulate the engine at its optimum operating temperature. The coolant must also have the correct mixture and chemical compounds to promote heat transfer, protect against freezing, and also inhibit corrosion. To keep your BMW operating correctly, it's important to check the level, strength, and overall condition of the coolant on a regular basis. You also need to change the coolant before it degrades to the point where it doesn't perform it's job adequately.
A fact that I keep hearing kicked around revolves around the reported findings of the U.S Department of Transportation, which states that cooling system failures are the leading cause of mechanical breakdowns on the highway. Not exactly surprising, since proper cooling maintenance is one of the most neglected areas of most cars.
One failure mode associated with dirty coolant is known as electrolysis. Electrolysis occurs when stray electrical current routes itself through the engine coolant. The electricity is attempting to find the shortest path, and impurities in the coolant often generate a path of least resistance that the electricity travels across. The source of this stray electricity is often from electrical engine accessories which have not been properly grounded. A missing engine or transmission ground strap can also cause the coolant to become electrified. Sometimes the path of least resistance becomes a radiator, a heater hose, or even the heater core. These components are often well grounded, and offer a ground path from the engine to the chassis by means of the semi-conductive path of the coolant.
Electrolysis can destroy your engine quickly. Although it's semi-normal to have very small amounts of voltage potential in your coolant system, values greater than about a tenth of a volt can start reactions between the coolant and the metal in your engine. In particular, electrolysis affects primarily aluminum engine components, resulting in pitting and scaring of the aluminum surface. This eating away of the metal can cause coolant system leaks, and in particular, radiator leaks around aluminum welds. Cast-iron components are also vulnerable, but typically the aluminum metal parts fail first. On BMWs in particular, electrolysis can be easily seen attacking aluminum cylinder heads. Figure 1 shows a picture of the thermostat area of a cylinder head that has been partially damaged by electrolysis. Notice how the aluminum has been eaten away, and eroded by the chemical/electrical reactions.
The process works somewhat like electrical discharge machines (EDM). These machines work by passing a large electrical current through metal, literally zapping away bits of material until nothing remains. Unfortunately, the electrolysis process works in a similar way, zapping bits of metal in proportion to the amount of electrical current passing through the coolant. A poorly grounded starter can literally destroy a radiator or head within a matter of weeks, depending upon how often the car is started. A smaller current drain, like an electric cooling fan, may slowing erode components over many months.
How can you test for electrolysis? Other than actually seeing visible signs of erosion, you can perform a current flow test. Connect the negative terminal of a voltmeter to the chassis ground. Test for adequate continuity by touching another point on the chassis - the resistance should be near to zero. With the engine cold and running, submerge the positive probe into the coolant tank, making sure that the probe does not touch any metal parts. The voltage should be less than .10 volts. If not, methodically turn off or unplug each electrical accessory until the reading reads below .10 volts. Have an assistant switch accessories (like the A/C compressor, heater blower, etc.) while you measure the voltage.
If an accessory doesn't have an on/off switch, test it by temporarily running a ground from the housing of the accessory to the chassis. Ground each component and check the volt meter. If the wire restores a missing ground connection to the accessory, then you've found a component with a faulty ground.
During this test, be sure to check the starter. Not only will a poorly grounded starter struggle to turn over the engine, it will also zap away tremendous amounts of metal in your cooling system. Watch the meter carefully when starting the engine. Any voltage spike will indicate a faulty ground connection.
Coolant System Additives
Many people are rightly skeptical of coolant system additives - there are a lot of myths in the automotive industry. Luckily, the coolant system additives are in the category of good practice, for reasons I'll explain here. It all begins with chemistry. Like today's modern oils, many of today's modern coolants incorporate some of the chemicals that help cooling and increase heat flow around your cooling system components. As more and more automotive components are made out of aluminum, and radiators become smaller, the use of these additives becomes more advantageous.
Aftermarket coolant system additives are known as surfactants. What is a surfactant? A surfactant or surface active agent, is a molecule that has a water-loving end (hydrophilic and water fearing end (hydrophobic). Localized boiling of coolant in the cylinder head can create large shock waves that can wreck havoc on your engine, particularly on aluminum components. Without going into too much boring detail, these surfactants also help to reduce the amount of air in the cooling system, and also control the amount of foam within the system.
In general, there are three main reasons why using these additives is beneficial to your cooling system. Firstly, they reduce harmful cavitations and foaming that may occur when your water pump is kicking out fluid at a rapid pace. This reduced foaming helps to prevent damage to aluminum surfaces. Secondly, the use of these additives aid in the transmission of heat from the coolant to the radiating surfaces within the radiator. Even if your car runs very cool, these additives add a extra level of protection in case a thermostat or similar component fails. Thirdly, the additives contain corrosion inhibitors. Most cars on the road have cooling systems that do not contain the ideal 50/50 water / antifreeze ratio that the antifreeze manufacturers design for. The additives help to minimize potential corrosion by maintaining adequate pH levels. Even if your antifreeze already contains surfactant additives, the use of these additional additives is typically beneficial because most cars are shortchanged on the 50/50 coolant/water mix.
In general, the benefits of additives like Water Wetter are:
Reduces corrosion due to rust, and electrolysis
Increases the 'wetting ability' of water and improves heat transfer, thus reducing cylinder head temperatures
Cleans and lubricates coolant system seals like those found in the water pump
Reduces the formation of foam and cavitations which can cause corrosion
Reduces the effects of 'hard water' in the cooling system
In general, the addition of these additives is cheap, and it's a proven benefit too - no snake oil here. Using the additives on a perfectly maintained car can also provide a significant margin of error in case something goes wrong. BMWs are infamous for cooling system failures - keeping the odds on your side can prevent a costly head gasket replacement.
It's important to keep your cooling system at the correct pH as well. Water has a pH of 7 and is considered neutral. Battery acid is highly corrosive and has a pH of about 2-3, whereas baking soda is very alkaline, and has a pH of about 10-11. In general, you want to make sure that your coolant has a pH greater than seven. Any pH less than that will result in an acidic mixture, which will start to corrode your engine. The corrosion inhibitors in additives and antifreeze are added specifically to keep the pH above 7. A properly mixed 50/50 split between water and antifreeze will yield a pH of about 8-9. Over time, the glycol (one of the main components of antifreeze) will break down and degrade, creating acidic compounds. The alkaline corrosion inhibitors must be adequate enough to neutralize these acidic byproducts over the life of the coolant. Minerals in the water, heat, dissolved oxygen, and other factors gradually deplete the coolant of its corrosion inhibitors. Once gone, the mixture will become acidic, and will begin to eat away at your engine.
Cooling System Maintenance - Checking the Level
It's very important to check your coolant level regularly, as this will help detect leaks that can siphon off coolant and cause overheating in your engine. You should regularly check the coolant level in your coolant reservoir, making sure that it is within the prescribed High/Low marks. These marks are printed on the side of the coolant container. The container is slightly transparent, and you can see through it slightly to see the current coolant level.
Your BMW will lose a little bit of coolant here and there over time due to evaporation from the reservoir. However, a significant loss of coolant over a very short period of time almost certainly signifies a leak in the system. Sometimes a leak can be seen when you park the car overnight. Often the coolant leaks out and then evaporates while you're driving, leaving no tell-tale mark of coolant on the pavement. If you suspect a coolant leak, visually inspect all of the hoses, the water pump, the reservoir, and the radiator for seepage or the 'weeping' of coolant out of seams and gaskets. Check the seal on the radiator cap. Check that the radiator cap is fastened securely - the way the BMW radiator cap is designed makes it easy to make the simple, yet deadly mistake of leaving the cap cocked - allowing coolant to leak out when the engine is running. If you suspect a leak that you cannot see, a pressure test from a professional mechanic can verify the integrity of your system.
If you can't find any visible leaks and the system appears to hold pressure, then check to make sure that the cap is good, and is rated for the proper pressure. Verify that the cap you have for your BMW is the proper one for your engine. Figure 2 shows an example of a proper radiator cap for the BMW 3-Series 325is.
If the system does not hold pressure, and you're still at a loss where coolant might be disappearing to, then you might want to start looking in the oil. A faulty head gasket will often cause coolant to leak into the oil. If you remove your oil cap and find a yellow murky substance, then you probably have a faulty head gasket. Figure 3 shows an example of what this mixture looks like. The oil level may be elevated and you will be able to see droplets of coolant inside the oil filler hole. If coolant is leaking past the gasket into a combustion chamber, you will see steam exiting out of the tailpipe, and the spark plugs will foul easily. In addition, the exhaust will be contaminated with the silicate corrosion inhibitors found in the coolant, and your oxygen sensor will be destroyed - plan on replacing it if you have experienced this problem. See the upcoming tech article on head gasket replacements for more information. Figure 4 and Figure 5 show what your oil may look like after the coolant and oil mix together. Figure 6 and Figure 7 clearly show drops of coolant after the valve cover has been removed.
If you can't discover what happened to the coolant, it may be because there was a temporary overheating problem and some of the coolant boiled over. In this case, top off the coolant and keep a very close eye on it. It's not uncommon for BMW overheating issues to suddenly destroy a head gasket.
Checking Coolant Strength & Condition
You should periodically test the strength and condition of your coolant to assure that you have achieved the optimum balance for your BMW. This is just as important for protection against heat as it is for protection against freezing. An imbalance between water and antifreeze levels will change the boiling point and/or freezing point of the mixture. A 50/50 mixture of water and ethylene glycol (EG) antifreeze will provide protection against boiling up to approximately 255° F (with a 15 psi radiator cap). This mixture will protect against freezing to a chilly -34° F. On the other hand, a similar 50/50 mixture of propylene glycol (PG) antifreeze and water will give you protection from -26° F to about 257° F.
If you increase the concentration of antifreeze in your coolant, you will raise the effective boiling point, and lower the freezing point. While this may seem beneficial on the surface, having a antifreeze content of greater than 65-70% will significantly reduce the ability of the coolant to transmit and transfer heat. This increases the chances of overheating. As with most things in life, it's a good thing to maintain a healthy balance.
Beware - you cannot accurately determine the condition of your coolant simply by looking at it. The chemical composition and concentrations in the coolant are very important - if the chemistry is off, then your coolant may be harming your engine.
As mentioned previously, it is important to keep the coolant fresh. The main ingredient in antifreeze, ethylene glycol, typically accounts for 95% of antifreeze by weight. It does not typically wear out, but the corrosion inhibitors that comprise the remaining 5% typically do degrade and wear out over time. Keeping the coolant fresh is especially important with engines that have both aluminum heads and cast iron blocks.
I recommend that the coolant be changed at least every two years, or every 25,000 miles. I'm not a huge fan of long-life antifreeze - if these longer-life fluids are mixed with conventional antifreeze (a very easy mistake to make), the corrosion inhibitors react and reduce the effective protection of the long-life fluid. If you do have this long-life fluid installed in your car, only add the same type of anti-freeze to the car. Don't mix and match regular and long-life fluid.
Unfortunately, it's tough to determine if your long-life coolant has been mixed or topped off with ordinary antifreeze. Although some coolants are dyed a separate color (like Dex-Cool in GM vehicles), when mixed with standard antifreeze, it typically isn't enough to overpower the bright green color. In general, unless you know the entire service history of your BMW, it's a wise idea to err on the side of caution, and use a shorter service interval for changing your coolant.
Okay, so how do you check the coolant in your system? I recommend using little chemical strip tests that measure how much reserve alkalinity is left within the coolant. The test strip changes color when immersed in the coolant. You can then compare the final color change to a reference chart in order to determine the condition of the coolant. Obviously, if the coolant tests poorly or is borderline, you should plan on replacing your coolant very soon.
An additional note - EG and PG antifreeze has differing specific gravities, so make sure that you use the correct type of test strip when testing your coolant. Otherwise, you may end up with false readings.
Changing the Coolant in Your BMW
Okay, so I've convinced you that your coolant needs changing. The good news is that it's relatively easy on the BMW 3-Series. Begin by getting a large drip pan to place underneath your car. My favorite choice is kitty litter boxes, as they are large, are made of plastic, and will hold a lot of coolant. The BMW 3-Series six cylinder engines will hold just shy of 3 gallons (10.5 liters), so make sure that whatever container you use is capable of holding all of that coolant.
With your BMW cold, elevate it on jack stands as indicated in our Pelican Technical Article on "Jacking Up Your BMW." Place the heater control knobs all the way on hot, turn the ignition to the on position, and turn on the passenger compartment fans to their lowest setting. Do not start the car. By turning the heater knobs on, you are opening the valves to the heater core, which will allow you to drain the coolant located in the core. For cars with electronic climate control, make sure the ignition is on and the heater is set to maximum heat.
On the right side (passenger side for US-cars) of the engine, just under the manifold, you will see the drain plug for the coolant. See Figure 8 for a photo of exactly where this plug is located. Place your collection container underneath the plug, as shown in Figure 9. Remove the plug and let the coolant empty out into the catch pan. BEWARE: I have found it nearly impossible to empty the coolant without having it spill on myself. Don't wear any decent clothes, and make sure that you are wearing safety glasses when working underneath the car. The coolant will empty out much like water comes out of a shower - it will spray all over, and will be difficult to catch 100% into your pan. Have plenty of paper towels on hand to clean up the spilled coolant.
When all of the coolant has been released from the engine block, replace the plug (use a new sealing aluminum ring) and tighten it to 25 Nm (18 ft-lb). Now, move onto the radiator. There should be a plastic drain plug at the bottom of the radiator, as shown in Figure 10. Position your drain pan, and slowly remove this drain plug. The stream from the radiator is a bit more predictable, and should empty in a steady stream, as shown in Figure 11. When all of the coolant is emptied out of the radiator, replace the plug. Tighten to 2-3 Nm (18-27 in-lb). Note this torque is very, very small - don't over tighten the plug as you may damage either the plug or the radiator.
With all of the coolant removed from the system, use a funnel and place it into plastic containers. One gallon spring water or milk containers make excellent storage containers for used coolant (Figure 12). Don't pour the coolant down the drain, instead take it to a recycling station. A note about coolant - it is highly toxic and dangerous to pets and small children. Used coolant should be packaged up right away. Less-than-intelligent animals seem to like the smell and taste of coolant, and will be attracted to it. Package it up and seal it off, otherwise you may find kitty dead in the garage one day - no joking. Rinse and dilute any contaminated areas with water.
Remove the small plastic bleed screw to the right of the radiator cap. On M3 engines, this screw is located on the thermostat housing. Using a large funnel in the expansion tank, slowly fill the car with new coolant. Use a 50/50 mixture of antifreeze and distilled water. Do not use tap water or spring water, as these have impurities that will contaminate your system. Distilled or ionized water is 100% H20, and does not contain any minerals, additives, or impurities. Fill the system very slowly, as it will take a bit of time for the coolant to get to all points in the system. On 4-cylinder cars, you will need about 7 quarts (6.5 liters). For the six cylinder cars, you will need 10.6 quarts (10 liters). M3 motors require 11.1 quarts (10.5 liters).
When the system is full of coolant, you will need to bleed air out of it. This applied only to the cars that have the expansion tank attached to the side of the radiator. Other BMWs with a separate, external expansion tank are self-bleeding. The procedure for bleeding these cars seems somewhat sloppy and not too slick. With the bleed screw removed, fill the expansion tank until fluid begins coming out of the bleed screw. Continue filling until there are no more bubbles coming out, as shown in Figure 13. This, of course will mean that plenty of coolant will spill all over your radiator, and down onto the ground. Have a catch pan ready to capture this coolant spill. When no more bubbles exit out of the bleed screw, tighten it to approximately 1 Nm (9 in-lb).
Now, run the engine until it reaches it's operating temperature. Turn off the engine and let it cool down. Then, top off the coolant in the expansion tank to the appropriate level, if necessary.
I'm sure one question you're about to ask is "what type of coolant should I use?" BMW has issued a 1991 technical bulletin, 17 01 88(1743), which details problems with what is known as silicate gel precipitation in engines. This is the 'green goo' (yes, it actually says that in the BMW Tech bulletin - gotta love those German translators) that results as a consequence of an antifreeze over-concentration in the coolant, combined with hard water, and the phosphates commonly used in many antifreezes. BMW factory antifreeze has been formulated to prevent this problem of silicate drop-out without any coolant performance loss. This antifreeze contains no nitrites and no phosphates. The part number for a one gallon container is 88-88-6-900-316, and it costs about $13.00 per gallon. Although I am always eager to find alternatives to BMW factory products, I would stick with the factory coolant for now.
Well, there you have it - everything you've always wanted to know about BMW cooling systems. Be sure that after a few days of driving, check the coolant level again, and top it off if necessary.
This technical article is made possible solely through the support of Pelican Parts. If you like what you see here, then please visit our online BMW catalog and help support the collection and creating of new and informative technical articles like this one.
here's an idea. How about a full diagram of a typical BMW cooling system, with the internals of the reservoir drawn out? you know, the little tube in there that cracks, and the float level sensor, and the bleed hose at the top of the radiator, that crosses over and sometimes clogs and causes you to chase overheat problems endlessly, etc... I am about to cut open a reservoir tank, cause i cannot find any info out there that show the internals and how these things work and why they are so darn complex... thanks!
March 5, 2013
Followup from the Pelican Staff: Thanks for the feedback. - Nick at Pelican Parts
Comments: I am collecting the materials to do a coolant replacement in my 2000 328i. I have located the engine coolant plug & given its limited accessibility believe it is a sure-fire opportunity to have coolant cascading down my sleeve and in my face. Would I get the same drainage if I removed the lower engine-radiator hose? Also, vehicle has only 60K miles & has not been driven hard, my wife's car. Hoses look and feel fine, but should I replace them as a precaution because of age?
February 5, 2013
Followup from the Pelican Staff: Sure it might not be a bad idea to replace hoses, 60,000 mile car while you're in there. One trick that I have for minimizing coolant spilling down my arm is to simply take a razor blade and cut the actual radiator hose while it's suspended over a bucket. This allows you to control the flow of the fluid and also minimizes the mess that you would have in your garage. In most cases old radiator hoses are difficult to remove from their fittings anyway and often require cutting. If the hoses are easy to get to that I would probably replace them. - Wayne at Pelican Parts
Comments: I just completed this task successfully. I used an old shower curtain and some cheap foil roating pans to catch the drips. It worked well. Thanks for the directions.
November 4, 2012
Followup from the Pelican Staff: Glad it worked out, thanks for the feedback. - Nick at Pelican Parts
Comments: At the overwhelming suggestions of the BMW CCA members, blogs, BMW salesmen/women from the various vendors, I took the plunge and spent a tidy sum on Evan's NPG+. First, it is absolutely necessary to get the ENTIRE residual water down to less than 5% of the entire radiator system. Once the system is at 5% or less of water or any other contaminants, then one can fill the system full of Evans. Provided there was no contamination, the Evans, which is water-LESS in nature could last up to 500k miles. Now the mileage isn't important but what is would be the lack of water to corrode and destroy the radiator and hoses. Well, The local BMW dealership refuses to admit to the benefits of Evans and wants the 50/50 mix used. I want Evans but I have no earthly way of getting the radiator to less thqan 5% water. Any thoughts? I have a 2011 N55 335i Sedan with 24k miles on it 90% Highway miles.
November 1, 2012
Followup from the Pelican Staff: You could remove the componenets and completely drain and dry them. Might be your best bet if you are having a problem. - Nick at Pelican Parts
Comments: hi guys can anyone help please
i have a 1992 model 520i bmw i am having a problem with the fuel tank building up pressure , when fulling petrol the attendent has to open the cap with caution cause the pressure pushes out to fast...how do i fix the tank so that it does not build pressure
October 22, 2012
Followup from the Pelican Staff: The vent on your fuel tank may be restricted. Locate the vent hose and check that it is clear. - Nick at Pelican Parts
Comments: NEED HELP!!! I HAVE A BMW 525I 95 AND IT RUNS HOT EVERYDAY. I FLUSH THE COOLANT SYSTEM EVERYDAY. AFTER THE FLUSH, IT DOESN'T RUN HOT THE REST OF THE DAY. THERE ARE CONSTANT AIR BUBBLES. WHAT'S WRONG WITH MY CAR????
September 25, 2012
Followup from the Pelican Staff: If there is air being introduced into your system you may have a faulty head gasket. I would perform a cooling system pressure test and see if coolant is making it into the cylinders. - Nick at Pelican Parts
Comments: i changed the water pump in my 93 325is it had green coolant in it so i drained the block and rinsed the radiator filled the system with blue bmw coolant it took a little more then 2 1/2 gallons of 50/50 mixed with distilled water do i need to worry about green goo!! thanks in advance
August 4, 2012
Followup from the Pelican Staff: Mixing coolant types in a NO NO, but if you flushed the system completely you should be OK. - Nick at Pelican Parts
Comments: i changed the water pump in my 93 325is it had green coolant in it so i drained the block and rinsed the radiator filled the system with blue bmw coolant it took a little more then 2 1/2 gallons of 50/50 mixed with distilled water do i need to worry about green goo
August 4, 2012
Followup from the Pelican Staff: Mixing coolant types in a NO NO, but if you flushed the system completely you should be OK. - Nick at Pelican Parts
Comments: Hi MY 1994 325I has a really bad coolant leak on the drivers side towards the steering column, I have tried to locate from where the leak is coming from but i am unable to see it. any suggestions?
June 25, 2012
Followup from the Pelican Staff: The leak could be from a coolant fitting or hose. Try using a mirror to inspect the area under your intake manifold. - Nick at Pelican Parts
Comments: hello Wayne. Very informative site. I am making this post to see if fitting a m3 thermostat housing with air bleeder is a real fix for what should be a simple task. I have recently purchased a Aussie 90 model 318i m40 engine 359000ks 2 previous owners and well looked after. I have never owned a bmw before and have been learning as i go. when i first purchased the car the temp was very erratic normal while driving but if at traffic lights temp would slowly head to the red. Better check that i thought. The car has a radiator with the tank attached to the radiator and had bled the system as per your comments above with no real results and experiencing similar problems to all the posts above. The car had only had a new radiator fitted not long before i purchased it so i looked elsewhere for an issue. First place i looked was the thermostat, replaced it and the housing but could only source a m3 housing at short notice. No big deal lots of aussie cars have this method of bleeding. Now due to the position of the bleeder on the housing to the fan i did not use it and only bled from the radiator. The problem was still there. Before i replaced more parts i decided to bleed system again using both bleeders open while engine running. This instantly fixed the problem. drove the car for a couple of weeks with no problems and have since dropped the coolant out of the car for varying reasons 3 times. Always bled using both bleeders and haven't had to re bleed once. It would be nice to know if using the m3 housing is an advantage or if it is that i am just lucky.
June 16, 2012
Followup from the Pelican Staff: You may have gotten lucky, hard to say.
At times removing trapped air froma cooling system can be the most difficult part of a cooling system service. I prefer to place the system under a vacuum when refilling, this removes all trapped air and makes refilling and bleeding much easier.- Nick at Pelican Parts
Comments: I have a bmw 540i 1999 smoke was coming out of the resevoir tank cooling cap which lets the evaporation seep out it was coming out of that. do I replace the tank or is it a thermostat if so where is the thermostat located? thanks
June 9, 2012
Followup from the Pelican Staff: The thermostat is located at the front of your engine, above the water pump.
Check that your engine isn't overhating, smoke should not be coming outof the reservoir. - Nick at Pelican Parts
Comments: Hi,need help please.I change water pump and a 3 way conector under air intake plastic conector goes on block ok now i bleed system a couple of times tempeture rise after sittig for like 30 minutes fans are on plus i have one extra just try t o protect engine and still goes to high no mixing on oil no head gasket problem , i did leave out thermostat ???is cuz of this that is getting hot , and upper and bottom hoses are hot like regular temp but needel inside goes to hot red and radiator is full of just water everything is hot but water is colddd ???why .now do i need that thermostat inside the engine to cool it down plus coolant in the system to avoid geting hot ??please help is my only car
May 24, 2012
Followup from the Pelican Staff: Sounds to me like air is trapped in your cooling system. I would locate the bleeders and try to refill and bleed your cooling system. - Nick at Pelican Parts
Comments: Oh, in the comment re: draining coolant and replacing with fresh coolant; my car is an 85 318i, or, E30/
Will also maybe need help with the fuel=pressure sensor and.or mass air flow sensor. Idling problem that I don't know is the idle sensors, or are.
I don't know! It is driving me crazy, but I really want to conquer this one!
April 8, 2012
Followup from the Pelican Staff: You will have to check the idle control valve and circuit. They are quite troublesome on older E30 models. This could be the cause of your idle issue. - Nick at Pelican Parts
Comments: Here I am again, after trying out so many things to fix what seems to be an idle or fuel or air problem== and I say IDLE if it's both fuel and air//exhaust.
This problem started when the Ambient Pressure Sensor lid came off, as the air-boot and air-box had somehow detached from the throttle housing.
So I have replaced the boot, the MAP mass ambient pressure- or what I call a barometer sensor, checked & replaced hoses, tune-up plugs, wires, fuses- about to replace relays too, and remembered my coolant had been topped off with a brand or style that Peak "Gold" coolant?, which my son told me was not a great choice- and would ruin my car.
So, I am thinking I will drain the radiator and hoses, at least I usually do that rather than have to climb under the car, alone, with it on jacks or stands, flush system with Dist H2O, and then replace fluid with regular 50/50 mixture. I used to keep my cooling system filled with greater water to EtOGlycol, up to 80 percent water, and never had a coolant problem. But, the book looks to this being a part of the problem/ I am also seeing green acidic nastiness at the ends of both hoses - throttle body and radiator, itself. This is a first for me!
My question is: IS draining the system, from 2 sources and not including the manifold, flushing with clean water, then draining and replacing again, a good way to go about this? *my SON refuses to help me with the car anymore since the answer is just NOT obvious this time!! So, thanks!
April 8, 2012
Followup from the Pelican Staff: if you want to remove all the old coolant from the system, drain what you can from the radiator and the engine block. Then if needed, you can flush the system with clean water. Then fill with a 50/50 mix of BMW coolant. - Nick at Pelican Parts
Comments: hoi wayne I have a 1999 323i replaced the radiator hoses coolant resovoir and removed the thermostat now i have so much pressure even after bleeding any ideas Sam in san diego???
March 7, 2012
Followup from the Pelican Staff: Did the vehicle overheat? There is not simple answer to why the system would have excessive pressure after replacing parts, that is unless something is installed incorrectly, creating a blockage. - Nick at Pelican Parts
Comments: I have a 1996 750 with a coolant leak. I saw what seems to be a tube that's missing a hose at the top rear of engine compartment. I wnat to know ehere to find a view of the entire coolant system for 750i series. Thanks
February 20, 2012
Followup from the Pelican Staff: Give our parts specialists a call at 1-888-280-7799 and they can help figure out which part or repair kit you need. Or possibly a repair manual to help locate the area of concern. - Nick at Pelican Parts
Comments: i have a bmw 320d and the heat guage goes into the red as you turn the ignition on, prior to this i was checking the interior fan fuse and pulled the centeral locking one by accident, now i cannot start the car. I have had a friend come over and check the system with a pc and the only fault on the car is that the coolant temp is 103'c and we cannot reset it.Could pulling the fuse caused this sensor to go faulty? dose anyone have an idea what to do next?
January 31, 2012
Followup from the Pelican Staff: If your vehicle will not start and the temp gauge reads hot, your DME may be offline or faulty. I would perform a system test using a BMW scan tool. - Nick at Pelican Parts
Comments: Hi I have a 95 bmw e36 compact and have an over heating problem. I changed the radiator and checked for leaks but there is none, The water pump was checked which is fine and I also changed the thermostat and fan switch but I am still getting the overheating problem any suggestions as to what the root of the problem may be?
January 29, 2012
Followup from the Pelican Staff: Check that air is not trapped in the cooling system. If system bleeds normally and no air is found, check for a faulty head gasket. - Nick at Pelican Parts
Comments: My k & n air filter was cleaned in a rush with water, oh no not dried!! driven for three miles up to temperature. Stopped the engine. Coolant boiled over and yes, creamy oil cap. Is this all bad, or will I be lucky after an oil change and a dry filter.. Any advice appreiciated.
January 9, 2012
Followup from the Pelican Staff: The foam on the bottom of oil cap is quite common and can be caused by condensation in your engine.
Coolant mixing with engine oil indicates a faulty head gasket. Confirm you have engine and coolant mix before digging too deep. Locate the source of the engine overheating, thermostat, water pump, etc.
I would think the air filter is a coincidence. - Nick at Pelican Parts
Comments: Need help please! The stupid plastic on the radiator broke, forcing me to replace it. While I was replacing it, I figured I'd do the whole maintenance, replacing a bunch of the cooling components. I went to pull off the coolant drain plug on the block, but the thing won't budge, in fact I am on the verge of rounding the whole thing. Any tips on freeing it up a bit?
January 8, 2012
Followup from the Pelican Staff: If it will not come out with traditional methods, it may be best to leave it alone. I would suggest vise grips, etc, but there is not enough room to get a pair in there. - Nick at Pelican Parts
Comments: Wayne, I have a 93 325IS with @165K miles, my problem is when the car is being driven heat blows out of the vents but when the car isn't moving red light, stop sign etc.. the heat goes from hot to cool then cold and eventually goes back to hot as I'm driving! The car ISN'T overheating, running hot, no steam/smoke is emitting from the engine or exhaust nor is any fluids leaking from the car! I've replaced the heater control valve, thermostat, water pump.....WHAT COULD BE CAUSING THIS ISSUE?
December 31, 2011
Followup from the Pelican Staff: You could have a restricted cooling system or a faulty water pump. If flow or heat increases while driving, this indicates that more pressure is needed tocirculate engine coolant. - Nick at Pelican Parts
Comments: hey, i own a bmw 330i 2001. lately ive noticed a coolant leak, checked cap its good. car runs good and has never overheated.
December 25, 2011
Followup from the Pelican Staff: I would locate the area of the leak by pressure testing the cooling system. Give our parts specialists a call at 1-888-280-7799 and they can help you find the tool.- Nick at Pelican Parts
Comments: Came up with an interesting problem with my 98 320i - The radiator plug Blue won't actually undo. It freespins! Any ideas on how to fix this?
December 16, 2011
Followup from the Pelican Staff: I've heard of this before, but I can't recall what the resolution was. If it's not leaking, then I would leave it alone, and see if you can empty the coolant from another spot. Otherwise, a simple coolant flush may turn into a radiator replacement project. - Wayne at Pelican Parts
Comments: I have a 02' 325i Manual Transmission.
What is the deal with the stupid radiator drain cock design.
I've checked the Blue drain plug and its O ring. It leaks Antifreeze from the thumb sized open hole above the drain plug area. I have read bits and pieces about the "Radiator Adjustment Screw? Do I need to replace that part - the Hex head with stem thing...that the blue plug goes in? Can it even be replaced without doing damage to the radiator tank?
December 16, 2011
Followup from the Pelican Staff: Some of these radiators can be a real pain - particularly if they are non-OEM or some type of superseded brand. They often use the same radiator for different cars, and simply plug the holes they are not using. Sometimes the plugs fall out, which may be the case here (can't tell from the photo). Frankly, I would just replace the radiator with a new one so that you're not fighting this for the next several months. - Wayne at Pelican Parts
Comments: I have a 2001 BMW Z3 with 117000 miles, 3.0 engine. All of a sudden the heater would only blow cold air. Checked coolant was low, filled it, then noticed expansion tank was cracked all around the seam. Replaced the expansion tank, drained the coolant from the block and the radiator. Refilled with 50/50 coolant mix using distilled water. Now the engine does not run as hot as it used to. The temp guage only comes up to about 1/4, when it used to come up to halfway between the blue and the red, and the heater only blows warm air, when before would blow nice hot air. What could be the issue? Thanks.
December 14, 2011
Followup from the Pelican Staff: You could have a faulty cooling fan clutch, for your mechanical cooling fan. If the fan clutch is ON all the time, it would over-cool the engine.
I would check the temperature of the heater hoses. Compare what the temp is going into the heater core and coming out of it. You'll want to be sure it is a problem witht he cooling system before diggint oo deep. - Nick at Pelican Parts
Comments: I have a 1997 E36 with close to 300000 miles on the clock. I loose coolant quite quickly, about 50% over a period of two weeks which equals about 1500 miles. No obvious signs of a leak, no water in the oil, heater works, thermastat is not working but no sign of a leak. Pressure tested and no problems at all. Car runs well otherwise. No puddles on the drive. Recently heater hose became detached and lost all fluid but replaired so not the culprit. Any suggestions as I use the car every day
December 10, 2011
Followup from the Pelican Staff: The coolant has to be going somewhere, I would be especially concerned at the rate you state you are losing it.
Pressure test the cooling system over a long period of time. If you do find any external leaks, remove the sprk plus and check for coolant in the cylinders. - Nick at Pelican Parts
I have a 528! BMW 1999 right? i flushed the water from the radiator out but when adding the anti freezer/ coolant in didn't even take as much as we drained out? and then I took it for a drive and it started to heat up, can you tell me why?
December 5, 2011
Followup from the Pelican Staff: There is air trapped in your cooling system. You will want to open the bleeder screws on the upper radiator hoses while filling it. Then run the engine at idle, let cool then top coolant up. - Nick at Pelican Parts
Comments: Hi. I have a 1996 bmw 328is that starts out at cold temp, and rises to red within 5 minutes of driving at normal speeds on residential roads. I find that after opening the windows for a few seconds, the gauge goes back to normal position in the middle. I hardly experience this issue driving on the highway. What may be the issue here? Thanks for your support.
December 4, 2011
Followup from the Pelican Staff: This is typical of a air trapped in the cooling system. You'll want to bleed your cooling system.
If no air is found, check operation of your thermostat.- Nick at Pelican Parts
I have a 1996 bmw 328is that starts out at cold temp, and rises to red within 8 minutes of driving at normal speeds on residential roads. I find that opening that after opening the windows for a few seconds, the gauge goes back to normal position in the middle. I hardly experience this issue driving on the highway. What may be the issue here? Thanks for your support.
December 4, 2011
Followup from the Pelican Staff: This is typical of a air trapped in the cooling system. You'll want to bleed your cooling system.
If no air is found, check operation of your thermostat.- Nick at Pelican Parts
Comments: Hi everybody!
I have a tremendous problem with my 316 i Compact 1994 since 2 months. Coolant leakage. There is no problem with, like water in the oil gasket type error, there is no sign underneath the car of any leak. Couple of weeks ago I changed the o-rings at the heater core connection, below, at the driver side. Also dried up all the old coolant leak that was underneath the carpet lot's. However; NOW it is VERY WET UNDERNEATH THE CARPET AGAIN!!!and the level has decreased substantially in the exp tank. Anybody out there who is familiar with these signs? Could it be a leak in the heater core itself but I havn´t seen any traces of leaks, coming from there underneath?? I presume there is only one tubing from the engine and one returning from compartement? Or is ther a third connection?
November 22, 2011
Followup from the Pelican Staff: COolant entering the passenger cabin is likely from a leaking heater core. Inspect the heater housing drain for sign of coolant, on a normal system the drain should be free of coolant.
- Nick at Pelican Parts
Comments: Hi again Wayne
Can you please reply to my lates quedtion dated November 12, 2011 about the expancion tank cap tighting and bleeding the cooling system I just received my parts from Pelicah and want to start with the work ASAP Tank you.... Cheers
November 19, 2011
Followup from the Pelican Staff: Replied to your earlier comment, thanks for your patience. - Nick at Pelican Parts
Comments: Hi there Wayne
Can you please tell us how much do we have to tighten the radiator cap on the expansion tank on the driver side of the car?
I recently made an order from Pelican which is on its way and one of the part is a new radiator cap and want to make sure I tight it right, I guess the one I had been using I did tight it too much, practically to the point it won’t torn a mm more. When bleeding the cooling system you mention to, fill the expansion tank until no bobbles com out of the bleeding hole, then turn on the car engine and keep on poring coolant until no more bobbles come thru the bleeding hole, with the engine on do I have to turn on the heater to simultaneously?
1997 318is BMW E36/M44
Thx 4 da broad help.
November 12, 2011
Followup from the Pelican Staff: Tighten the cap until it stops, not over-tight, but you will feel it stop.
Bleed as you described, then turn heater on full hot and blower on medium speed. This will help to circulate engine coolant.- Nick at Pelican Parts
Comments: if was very informative
November 11, 2011
Followup from the Pelican Staff: Thanks for the feedback. - Nick at Pelican Parts
Comments: I have a 2004 BMW 325xi that is leaking coolant form a hose under the car. There is a metal box connected to the bottom of the expansion tankdrivers side, it has 2 hoses connected to it. What is the box called??? the plastic fastener is leaking......
November 7, 2011
Followup from the Pelican Staff: That would be the transmission cooler. Check if is the raditor that is leaking from behind it. - Nick at Pelican Parts
Comments: hi:i need some help pliz . i have bmw 318i 2ooo model. i was having overheat problems coz of water pump and fanthen ive fixed them but fan i fix volvo car fan .after that my car was very fine without any problems.after some few months like 3 to 4 months my car start giving the same problem .is that bcoz of fan for volvo car wich i fix or is there something else. the engine of car ,radioter,fan,water pump are all fine but my car still go overheat,so av been confused about this , plizz any help about this ? and thanks a lot,my prayers .
November 4, 2011
Followup from the Pelican Staff: Check if the thermostat is operating properly. If it is faulty, it will cause the engine to overheat. - Nick at Pelican Parts
Comments: Thanks for all that very good info.I have a BMW x3 2006, the dashboard indicator for fluids came up should i just add coolant? or have the cooling system flushed first?.
October 26, 2011
Followup from the Pelican Staff: I would top the coolant up, to prevent a problem until you can service it.
Check that the system is free from leaks, then flush the cooling system if needed based on mileage. - Nick at Pelican Parts
Comments: I just Fix radiator coolant tank water pump and I'm keeping pressure t but im loseng fluid but no leak can somebody help me out
October 21, 2011
Followup from the Pelican Staff: If you cannot locate an external leak, check if the floor is wet on the passenger side. You could have a heater core elak. - Nick at Pelican Parts
Comments: Help!! I noticed lots of white smoke billowing from my 2004 330I tailpipe!my low coolant light is on and has been for a couple of weeks, but whenever I have it checked, it's fine. My car seems to be in good shape aside for the hard idle..
October 14, 2011
Followup from the Pelican Staff: You could have a faulty head gasket. Pressure test the cooling system and check if coolant in entering the cylinders. - Nick at Pelican Parts
Comments: Hi, same situation with redeevee on 5 oct.2011. mt car is 316i lux touring auto E30 1993. thanks.
October 14, 2011
Followup from the Pelican Staff: I cannot find the comment relating to your problem. - Nick at Pelican Parts
Comments: hello.my heater only blows cold air, i changed the thermostat, the coolant.what other reason might there be that it dosent blow hot air?
October 13, 2011
Followup from the Pelican Staff: Check operation of your heater control valve. See if the heater hoses are hot or cold, the valve may not be allowing hot engine coolant intot he heater core - Nick at Pelican Parts
Comments: BMW 318i 2001 overheated when i was driving n i was a steam coming from the horse pipe that come from the engine. Any help will do pls
October 11, 2011
Followup from the Pelican Staff: Top up and bleed the cooling system. Then check that the water pump and thermostat are functioning correctly. - Nick at Pelican Parts
Comments: Hi after a bit of help, i have a bmw 330d and it overheats only when drivingnot when ideling even if you leave it there for an hour i have replaced the water pump, thermostat,header tank and viscious fan and it still overheats when driving any ideas?
October 10, 2011
Followup from the Pelican Staff: If the engine overheats while driving, this could be from a head gasket leak. Check that the cooling system is free from air. If it is, inspect the head gasket, the cooling system should be free from exhaust gas. - Nick at Pelican Parts
Comments: hi,i hav an e36 1995 model.put coolant in other day.but didnt bleed it properly.next day it was steaming and flowing out.trying to bleed all air bubbles out 2day,but they just keep comming.i had not got heater on though,just read that here.ive just bleeded again wth heater on full blast and finaly bubbles stopd.il bring for a good drive later thanks for nfo
October 6, 2011
Followup from the Pelican Staff: Thanks for the feedback. Glad it worked out. - Nick at Pelican Parts
Comments: The thermostat, auxiliary fan, radiator and water pump have all been replaced recently on my 1995 325i by a radiator shop. The car recently was steaming so I took it back to the shop. We noticed that the radiator cap was not tightened properly. I had removed the cap a couple of days before, and did not tighten it. The shop topped off the coolant and tightened the cap. The temperature gauge now indicates hot after just a couple of minutes of driving the car. The gauge fluctuates from the red hot zone to the middle, mostly in the red zone. Anyhow, when I open the hood, the engine seems fine, there are no signs of the car overheating, or leaks, but again the temperature gauge is in the red zone. Any suggestions?
October 5, 2011
Followup from the Pelican Staff: I would check actual engine temperature using a thermometer. If the engine is in fact running at normals temps and the gauge is int he red, you may have an issue witht he coolant temp sensor of the gauge. Does the cooling fan come on when the gauge is in the red? This would indicate the DME also sees the hot condition. - Nick at Pelican Parts
Comments: hi i have2003 325i oil is coming in the radiator from the engine
September 24, 2011
Followup from the Pelican Staff: You could have a faulty head gasket. Pressure test the cooling system. If the system will not hold pressure and there are no external leaks, the head gasket could be faulty. - Nick at Pelican Parts
Comments: I have a 2006 325I that overheats at will, my mechanic recently replaced my thermostat and engine coolant temperture sensor. My car still continues to overheat at will. My mechanic did bleed the resivoir at least 5 times to remove any access air. It still continues to overheat. When my car overheat, there is no steam coming from the engine or hoses. Does anyone have any idea of what the problem maybe?
Thank you in advance!
September 17, 2011
Followup from the Pelican Staff: You're going to have check if the engine is in fact overheating. Do the radiator hoses indicate the engine is overheating? Are both hoses the same temp? If the hose close to the thermostat is colde and the others are very hot, the thermostat could be faulty. - Nick at Pelican Parts
Comments: What productions do I follow to change the fan clutch on my 1997 328is?
Comments: Hi I’m experiencing a tiny leak if any put it comes from a Y connector tube located behind the engine head, very near to the valve cover, at rear area. So I did found the parts number but can find it on your catalog, practically I only need the "o-ring" since the connector is ok!
This is the O-ring Part Number
8- O-Ring 26,5X2,5 1 11511739691
9- Connector 1 11531743679
THX for the info
August 30, 2011
Followup from the Pelican Staff: Thanks for the feedback. Glad you got your vehicle fixed. - Nick at Pelican Parts
Comments: STEVE WITH THE 328I. HONESTLY I WOULD REPLACE THE RADIATOR. THE LEAK LOOKS LIKE ITS ON THE SEAM AND CAN NOT BE FIXED WITH ANY APOXY.
August 28, 2011
Followup from the Pelican Staff: Thanks for the input. Appreciate it. - Nick at Pelican Parts
Comments: I have BMW 316i 98 modle, aproblem I have is if I drive for about 80km at speed of 100-120. my water level drops to about 1.5 litres less.I have checked around I could not see any leakage both when the Engine is off or running.could it be air condition leads to that ?please advice thanks
August 22, 2011
Followup from the Pelican Staff: You're going to have to pressure test the cooling system. Check for any external leaks, including at the heater core. If none are found and the system does not hold pressure, you could have a faulty head gasket. - Nick at Pelican Parts
Comments: hello since i drained and flushed the radiator on my 1990 318i 4 cyl. the temp. never goes higher than a quarter on the gauge. also the heater only blows warm air not hot .can you help me
August 17, 2011
Followup from the Pelican Staff: Check that your cooling fan isn't ON all the time. Another possible cause would be the thermostat stuck open. - Nick at Pelican Parts
Comments: hi there,
98 328i leak upper right just under metal bracket, any guesses on where crack or leak really is under that? any usual spots for a leak under there? i don't see an actual bubble spot, just wet under metal piece, it's a slow leak under pressure. was gonna try and epoxy it right there but don't want to make a big blob there if leak is under metal or deeper in, any thoughts? thnx
August 14, 2011
Followup from the Pelican Staff: I would replace the radiator. The seal at the side tank looks like it is leaking. - Nick at Pelican Parts
Comments: i have a 1998 3 series and it is leaking coolant in between the coolant bottle and the radiator. can this be fixed or a new one is needed? The engine has overheated twice for few minutes. Has this done any damange to the engine
August 13, 2011
Followup from the Pelican Staff: it could be the reservoir leaking or the radiator. Pressure test the cooling system while monitoring the area of the leak, try to pinpoint the case. If unable to, replace the reservoir and the radiator. - Nick at Pelican Parts
Comments: Hi, I have a BMW 316i, year 2000, and I have just replaced the radiator as it had a crack in it and I have followed your directions on bleeding it, But steem and coolant seems to leak out of the lid on the expansion tank, and the coolant is boiling although the temprature gauge is at half way, could this be that i have been given the wrong lid? or any suggestions??
Thankyou Much appreciated Josh
August 2, 2011
Followup from the Pelican Staff: You may have air trapped int he system. Try bleeding it again. - Nick at Pelican Parts
Comments: I have a 2002 BMW 330CI. I was pulling up my driveway and heard a pop then immediately saw steam rising my my car and lost all my anitfreeze. It was like a river. No warning signs appeared at all. What could this be?
August 1, 2011
Followup from the Pelican Staff: The pop noise could be a radiator hose failing at the plastic fitting, or the radiator failing. I would pressure test the cooling system and locate the source of the leak. - Nick at Pelican Parts
Comments: I have a 92 325is. I have been having problems with overheating. I have had the water pump and thermostat changes and refilled the radiator as you showed. I seem to me getting a lot of ptressure buildign up in the cooling system. I have oil level is good and the car does not smoke out the tail pipe. The pressure is enought to keep forcing coolant out the cap. I'm thinking that I have a head gasket problem. Could my assumption be correct?
July 31, 2011
Followup from the Pelican Staff: If the system is building pressure and overheating, especially when under load, you may have a faulty head gasket. Check the cooling system for combustion gases. This is the best way to tell. - Nick at Pelican Parts
Comments: Today I flushed the cooling system, the previous owner of my 97 M3 used green coolant, and I am also missing the aux "pusher fan". I got the blue stuff from BMW along with a new reservoir and upper and lower radiator hoses. When I was installing the hoses I found it easier to access the clamps with the K&N cone filter and elbow removed... After flushing the block and radiator with water and capping the system, I filled it up, bled the tank as described...lots of bubbles came out.... Added a little Water Wetter to the mix and seems to be working good. Only concern is that the O-ring on the the radiator cap on the inside threaded part came off and was resting on the new reservoir. it fell in the reservoir.....problem??? The main concern, when I assembled the system and began to add coolant/h20/waterwetter I ran the engine to open the thermostat to suck the coolant into the block while bleeding it. Only thing is that I left the elbow and the KN filter off while running the engine, and now the ASC light is on. I cant get it to turn off. This happened once before when I removed the filter for cleaning but I was able to tap on the injector terminals and disconnect/reconnect the battery and the light was of, unless turned on. Ever since running the engine w/o the filter and inducing new coolant the ASC light has been on on my dash, and the switch wont turn it off... Any help?
July 3, 2011
Followup from the Pelican Staff: To clear the ASC fault, you will have to read out faults using a BMW scan tool. Address the problem that is setting the fault codes, then clear the fault codes using a BMW scan tool.
As far as the )-ring goes, I would fish it out so it doesn't end up lodged inthe cooling system somewhere. - Nick at Pelican Parts
Mi coche es e36 328i cabrio 1996.Tiene139.00km. Está como nuevo. Cuando lo pongo a 4.000rpm va perfecto todo el tiempo. Pero si lo pongo a 5.500/6000rpm a los 10 minutos ya comienza a tirar refrigerante por el tapón del recipiente. La bomba de agua, el viscoso y el tapón fueron cambiados hace 10.000km. El agua no hace burbujas. Tampoco sube la temperatura mientras conserva el líquido, por supuesto. Ya no sé que hacer. Los anillos obturadores que van en el vaso de expansión, ¿tendrán algo que ver? ¿Qué debo hacer? Gracias . Un saludo.
July 2, 2011
Comments: james: the head gasket is going, milky stuff in the cap is not normal, that is coolant leaking into the engine
328OWNED: blocked radiator, had it myself.
June 21, 2011
Comments: Update: I forgot to mention but my model is a 2000 BMW 323ci. I just went to check this morning and it seems the coolant tank is cracked big time. For now I can't tell what else is damaged but at least I know where it is actually leaking and its not from the radiator itself. Does that happen often?
June 14, 2011
Comments: Hi, so yesterday on a mildly hot day 88 degrees F I drove about 10 miles total and parked it at work around 4pm. I get out and as I'm walking away I a loud and long hiss coming from my car. Smoke comes from under my hood and 10 seconds after hissing and smoking the coolant fluid pours out! Later in the evening I poured water into the coolant tank and it comes flowing out as fast as it is poured in. I was wondering if an external collision may have caused this. I hit a dog 2 nights before and it was midnight in the middle of the country side so I didn't want to stop. I drove about a mile or two until I got to a well lit area and got out to inspect the damage. No real damage to the bumper but unfortunately I dragged the dog all the way. It looked like a full size beagle. I heard a loud whirring on my drive back home but it went away the next morning but it happened that afternoon. Can that possibly explain the sudden leak? Last week it reached up to 98 degrees and it ran fine.
June 14, 2011
Comments: my friend has a 04 318i m3 and has only had water in the radiator no coolant for about 12 months. It now blows white smoke maybe steam out of the exhaust. Also when i removed the radiator cap there was a white milky substance inside and around the bottom of the cap. My friend was advised that this milky substance is quite normal in bmw's.Any suggestions
June 11, 2011
Comments: I have a 97 316ti Euro model and I am trying to track down a part. The 90 degree plastic piece that the upper radiator hose connects to on the engine block. I can't seem to find this part. I am currently living in Spain, but I have an American mail address I can ship parts to. Any idea who I can aquire this piece from, and what it is called?
June 4, 2011
Comments: Hello I have a 98 328i and suddenly came up with an overheating problem. I Have Changed The Thermostat,Thermostat Housing & Water pump , The Top Radiator Hose Becomes Very Hot & The Bottom HHose Remains Cold, I've bled the system couple times and still no difference, and aslo the antifreeze in the tank remains cold I Don't Know What Else To Do! Any Suggestions ?
May 31, 2011
May 29, 2011
Comments: Hi the auxillary drive belt on my 2002 year 318i se with the 2litre n42 engine failed. I drove for a short while like this ie driving getting up to speed then turning the engine off and coasting. I have fitted a new belt and was wondering how to bleed the cooling system,i lost about a litre off cooland,cant seem to get hot air through the heaters but the car is not overheating and stayes where it always has on the temperature gauge. Thanks
May 29, 2011
Comments: On my 97 M3, the block plug is behid an O2 sensor. The reason I mention this is that it is not an unobstructed view, which made it difficult to find in the first place. Not to mention, the plug cannot be removed without first removing the sensor. I hate dealing with loose O2 sensors: I wrapped it in cloth to protect it from any impact but neglected to further wrap it with something to protect it from getting coolant on it. Turned out not to be a problem, but something I would do if I ever remove the coolant again.
May 23, 2011
Comments: i have a bmw 520i 126k miles running perfectly til yesterday, drove for 40 mins stuck in traffic for app 10 mins and temp guage shot up to red,blew off top radiator hose and lost some coolant, had to get towed, no steam from exhaust, car still runs but unsure what problem is???
May 21, 2011
Comments: I've read articles on bleeding the cooling system and am a bit unclear about one point in the process. I have a 94 E36 convertible with a 1.8L engine. I know the vehicle needs to be elevated to make sure the bleeder screw is the highest point in the cooling system and that you fill the cooling system until bubbles are no longer present at the bleeder screw. My question is this. Should this be done with the vehicle off or running? I'm used to American cars where you run the car to purge the air. From most of the instructions I've read online, they say nothing about starting the car.
May 18, 2011
Comments: I am no mechanic, but decided I would perform an oil change and a radiator flush on my perfectly running 1997 320i BMW. Hindsight I didn't find this website until after the fact. So... I only drained the plug as shown in Figure 10 with the car off and am pretty sure I didn't have the heater on. I then put in a new 50/50 mix through the large radiator cap..Not the small bleed screw as shown in Figure 13. My problems are listed 1 Overheats and steams somewhere around large hose at top of radiator 2 Heater does not blow hot air. Since then I've started the car and brought it up to normal operating temp and have added 50/50 throught the bleed valve, but it never fills all the up. It is just putting more in the main radiator, but still have the same problems. What should I do? I regret trying to do the maintenance myself to save some $, but have probably cost myself three times as much as it would have originally cost if not more. Can you offer me any advice? Thank you!
May 17, 2011
Comments: what is the red light next to the ABS on the dash board mean is any one please tell me what that mean and how to fix thank you
May 17, 2011
Comments: Hi thanks for the guide everything worked out perfectly with a new radiator however I replaced the double temp switch and dont remember what wires go where. Help!
May 13, 2011
Comments: Hi Wayne
Once again thank you so much for the broad info you provide to us thru all these interesting & helpful articles
1. Can you please tell us the proportion of additive we should pour to the cooling system?
2. I recently did a complete flush to my Bimmer, I used 50/50 OME BMW Coolant/Distillated water, can I pour the additive directly to the radiator expansion tank or the additive has to be mix with the 50/50 before refilling the car?
3. When I did the flush to my 1997 e36 318is euro version I drained the old coolant thru the blue plastic screw on the bottom of the radiator expansion tank. Is this all right or I had to look up for the engine coolant drain metal plug, as you mention on your article, remember that my car is a Euro version 1997 e36/M44 318is? 4. If so, where can I find this metal coolant draining plug on my car?
Again thanks so much for your time & help.
May 7, 2011
Comments: Hi Wayne. My mechanic replaced lot of cooling system parts and the parts like a/a belt to save money in labor in long run .I spend amost $600 just in parts.I got them from Pelican Parts by the way. My car is BMW 325i 2001.We missed two hoses, heater hose 64-21-8-376-153/21 and water pipe 11-53-7-502-525/9. How critical to have them changed? As far I know the fist one is piece of cake. Am i rigth about this? How much time in labor we are going to spend of changing this hose? The second one is hard to have changed? Would you tell my why? What is the aprox. time in labor is going to be? My car runs just fine. My thinking to get done just get the water hose.Thank you so much for providing OEM parts for resonable price.
April 30, 2011
Comments: Hey i have a 96 328i. The other night i was driving in the rain and i had to defroster on, i turned it off and then turned it back on, and now nothing comes out. No hot air, no cold air and i have no clue what could have went wrong. Help plzz
April 17, 2011
Followup from the Pelican Staff: It could be the infamous control unit problem with these cars. There is a capacitor that burns out on the board that needs replacing. If you search via Google, you will find a few article on replacing this, if this indeed is the problem. - Wayne at Pelican Parts
Comments: dear wayne i have a 1995 bmw 525i that i just replaced the radiator the water pump thermostate and clutch fan on and the damn thing is still blowing cold air and sometimes overheats i have bled the system and still nothing please help
April 12, 2011
Followup from the Pelican Staff: Blowing cold air instead of hot air through the heater? Sounds like a broken heater valve, or a massive air bubble in the system. I'd bet on air bubble. If you are having trouble bleeding the system by normal means, you can try pulling a vacuum on the system using a port attached to where the radiator cap fits. This is a standard procedure for Porsches, but it can also work for other cars that are having issues. Also try bleeding the car many times, at cold and warm too. It's probably just a bubble in there. Make sure the heater and fan are set to ON when you bleed. - Wayne at Pelican Parts
Comments: follwed the instuctions above, but I'm not getting any heat through the heater core/defroster any suggestions, do I have air in the system
April 7, 2011
Followup from the Pelican Staff: Probably. I would rebleed your system again when it's both cold and hot. Be sure to keep the heater turned on during bleeding. - Wayne at Pelican Parts
Comments: Hi I have a bmw 316 and i have an overheating problem now first off all there is no thermostat in it if the car has no thermostat would it still over heat? i have one ordered im just waiting for it but how would it still over heat without a thermostat. i have bled the cooling system several times and im not too sure if im doing it right, i opend the bleed nipple and hot steam is just coming out constantly how would i bleed it properly would i have to start bleeding it from cold? cheers
April 7, 2011
Followup from the Pelican Staff: These cars are notoriously difficult to bleed. I'm not sure what in particular is wrong with your car, but you might want to check to make sure that the radiator is not clogged and is properly cooling down the coolant as the car runs. If there is no thermostat, then the car should be sending all of the coolant through the radiator as it runs. - Wayne at Pelican Parts
Comments: IM HAVING AN OVER HEATING PROBLEM THE CAR IS A 98 328IS I TOOK APART THE THERMOSTAT NO LEAKS IN SYSTEM BLED IT SEVERAL TYPE STEAM COMES OUT OF THE BLEED SCREW I FILLED IT NOSE UP SHOULD IT B ON WHEEL RAMPS OR A NICE ANGLE DRIVE WAY OK? IM SO FRUSTRATED WORKED ON THIS THING FOUR LAST FOUR DAYZ NONE STOP IT RUNS OK FOR A BIT THEN AT ILDE OVER HEATS I HAD A HOSE EXPLODE B4 I DID THE THERMOSTAT HENCE WHY I DISASSEMBLE THE STAT...ANY HELP OR ANYONE CAME ACROSS THIS B4???HELP I JUST BOUT THIS CAR MY OLD 325I HAD SIM PROBS N I BELIEVE WARPED THE HEAD DNT WANT IT TO HAPPEN TO THIS ON ITS A GREAT CAR...
March 21, 2011
Followup from the Pelican Staff: I hear your frustration. I would repeat the bleed on the car, and I would also replace the radiator cap. The cap is designed to actually release pressure when it gets too high in the cooling system - if the cap is defective or worn out, it will not release this pressure and you will have leakage problems. - Wayne at Pelican Parts
Comments: 1998 i 28 overheating.I chek water pump,its look like new.Replaced thermostat.Still blowing cold air inside and anifreeze won"t curculate thru the sistem.Uper and lower hoses don"t have no pressure at all. Can anybodu suggest what can I chek next? Thanks
March 9, 2011
Followup from the Pelican Staff: You might have a serious air bubble in the top of your engine that is not allowing coolant to reach the thermostat. Bleed the entire system a few more times according to the instructions in my article here, and that should make a difference (hopefully). - Wayne at Pelican Parts
rich needs help
Comments: hi again thanks for the reply just another question there is quite a bit of pressure in the top hose i did replace the thermostat before i had this trouble, the car doesn't over heat or anything and the rad should it be hot all over thanks
February 24, 2011
Followup from the Pelican Staff: Yes, I would remove the radiator and have it checked for clogs if you think you have an issue. The radiator should *not* be hot all over, as it cools the coolant as it falls through the radiator. The top should be hot, the bottom should be much cooler. If the car is not overheating, then I would probably not worry about it too much. - Wayne at Pelican Parts
rich needs help
Comments: help top rad hose getsreally hot and the bottom one stays freezing cold, and the rad is only getting hot by about 4 inches at the top the rest of the rad is freezing thanks
February 22, 2011
Followup from the Pelican Staff: Can you feel water rushing through the top radiator hose? Hot on top and cold on bottom is typically a sign that the radiator is actually working. If it were completely clogged, then the top wouldn't really get hot as the water wouldn't be flowing into it. If you're not sure, then remove the radiator and take it to a radiator shop and have them flow test it. - Wayne at Pelican Parts
Comments: The radiator/expansion tank cap was replaced 4 days ago when I had the radiator and hoses changed. The car didn't leak any coolant for 4 days and boom all of a sudden its leaking again. I have been dealing with this issue for 3 months now and my mechanic can't find the problem other than changing all the cooling system components. All that is left to change are the heater hose but they looked fine no leaks from there. Any other suggestions that I can do to resolve this problem would be great.
February 20, 2011
Followup from the Pelican Staff: The only other suggestion I have is that maybe the wrong radiator cap has been fitted? - Wayne at Pelican Parts
Comments: My car was leaking coolant about three months ago and it was determined that the water pump need to be changed which i did. The car was fine and then it started leaking coolant again. This time it was the thermostat. Got that replaced too. Few days passed and the coolant light came on when driving home. I noticed a big puddle of coolant under the car. My expansion tank cracked. Replaced that too. A week later leaking again. This time it was the lower radiator hose. Even though my car never overheated or shown any signs of overheating I decided to change both upper and lower radiator hose and radiator. I pretty much overhauled the whole cooling system in my car and yet again 4 days later my car is leaking coolant. What is going on? Is it pressure in my system that will blow a head gasket or what? Please help.
February 20, 2011
Followup from the Pelican Staff: The radiator cap is designed to regulate pressure in your cooling system. If the cap is old or faulty, then you may have too much pressure in your system, and that may cause components to fail, as you have seen here. It doesn't sound like you replaced it yet, but I would replace the radiator cap and see if that makes a difference. I have a hunch that it will. - Wayne at Pelican Parts
Comments: Hello Wayne,
I have a 1994 BMW 318i and yesterday I had a bad leak and it was coming from what looks like a water manifold under the intake manifold against the head.The plastic piece that the hose hooks to broke completely off.The hose goes up into the intake somewhere.What is that water manifold part called that those 1" or so hoses connect to?
Looks like a hard job to replace
Thanks for your time
February 12, 2011
Followup from the Pelican Staff: I can't easily tell without a picture - I invite you to post one here in the forums. I'm just taking a wild guess that it's your thermostat housing that broke off. If you check our tech section here on thermostat replacement, you will find complete instructions, and it's not that difficult. Be sure to completely re-bleed the coolant system when you're done! - Wayne at Pelican Parts
Comments: Hi Wayne- The Copper Washer you listed is for the oil drain. Is it the same one for the coolant drain see my earlier comment- you reference a "new aluminium washer"
February 12, 2011
Followup from the Pelican Staff: Sorry, I corrected my response - thought you meant the oil drain plug washer. - Wayne at Pelican Parts
Comments: 03 540i - You mention replacing the sealing ring on the drain plug at the block. Got a part number? The only thing I could find on the site is a box of 400 sealing rings. Not terribly helpful for us DIY, only own 1 BMW-kind of guys. Thanks.
February 10, 2011
Followup from the Pelican Staff: No sweat, it's Part # 07 11 9 963 200, Aluminum Washer
14 X 18 X 1.5 mm, Block drain plug. - Wayne at Pelican Parts
Comments: have a 2003 325I BMW, coolant level keeps droping everyweek, but can not locate a leak, or see no smoke anywhere, any sugestions what could be happening with the coolant? or what could be the problem?
February 8, 2011
Followup from the Pelican Staff: Hmm, the coolant must be disappearing somewhere. In my experience, there's really only three places it can go:
- Into the oil as water-oil mix (you'll see the oil turn milky)
- Into the exhaust (you'll see steam come out of the rear tailpipe)
- Leaking out of the system through a crack or hose (you'll probably see drips on the driveway
Only the first option is easy to spot - the other two require some additional investigation. You may be leaking coolant out of a busted hose right onto the exhaust manifold, and it may be evaporating instantly. You can sometimes hear it happening, particularly right after you turn the car off.
- Wayne at Pelican Parts
Comments: what is the right radiator cap pressure for an 82 320i? BMW specifies a 14 LB/1 Bar cap. But the auto parts shop databases call for a 16 LB cap. I'm more interested in longevity and reliability than performance.
February 4, 2011
Followup from the Pelican Staff: I don't have the exact specs on this particular cap, but the correct part number is 17-11-1-100-848. The one we sell is manufactured by Reutter, and is a high quality brand that should be the correct pressure for your car. In general, the difference between 14 and 16 is probably not going to make too much of a difference. - Wayne at Pelican Parts
Comments: BMW 328i , E36 ,1997 - replace water pump , fan clutch , fan , thermostat , thermo-housing . Antifreeze and water done . bled system . NOW !!!! Let the car idle for about 30 minutes , temperature normal . But whilst idling there's white steam coming from exhaust , then temperature hit the red ? what now Wayne ???
February 2, 2011
Followup from the Pelican Staff: Hmm, steam coming from the exhaust is never a good thing. It seems to indicate an issue with the head gasket. I would reckon that you installed all of these new parts because you had a previous overheat condition? If yes, then it seems like your head gasket may be compromised, and you might have to pull off the head to replace it. - Wayne at Pelican Parts
First off, 1997 328is!
I changed my coolant using the DIY on the site. When I was filling the coolant tank, I never had fluid come out of my bleed screw. I figured if I ran the car a bit and cycled some coolant through all the coolant would leave the fill tank and I could add some more and then bleed it then.
I ran the car and the level dropped, but when I turned the car off it shot back up. I tried squeezing the hoses to/from the radiator and nothing but air comes out of the cap/bleed port. I ran the car for about 7 minutes and it didn't get up to running temp, but the needle was moving and air was starting to get warm. I would think that means that the heater core has fluid in it and not air?
So what I'm worried about is a pocket of air being in the block? And what I'm scared might happen is even though the fluid on the temp sensor for the gauge is at normal temp, the block itself is over heating. I don't THINK that happened tonight as the car was only running 5-7 minutes and I saw no steam or smelled anything odd, but I want to keep that from happening.
So anyway, where do I go from here? I KNOW there isn't enough coolant in the car because if my math is rightwhich it is, confirmed by a unit conversion the car should hold just shy of 3 gallons of coolantbecause it's a 6 cylinder...I don't even have two gallons in the car yet.
Any help would be greatly appreciated!
January 13, 2011
Followup from the Pelican Staff: Simple - don't overthink the process. Fill the car up, and then start the engine with the bleeder valve open. Continue to let the car heat up, adding more coolant to the tank as necessary. When the coolant starts to come out of the bleed screw, then close it. The car should be bled at that point. Make sure that the heater is on too during this process. Hope this helps... - Wayne at Pelican Parts
Comments: this is a great walk through thanks a lot, i recently bought a 95' 525i for 800$ i never was a Bimmer fan before but its in good condition cant beat that deal!
January 8, 2011
Comments: Wayne, My mechanics replaced the thermostat, tested the cooling system for exhaust was ok, tested compression. The fix lasted about two weeks and I "blew" the top radiator hose again last night. It's a quick fix and I bleed the top of the radiator frequently. Mechanics are now going to replace the expansion tank some plastic debris in there. Do you think running higher antifreeze proportions might help prevent foaming? I noticed the last radiator repair guy also put regular antifreeze in there and not the green BMW stuff. Tim
pickenpost Comments: I have a 99 E36 328i. I had the radiator tank replaced after the plastic neck on the top of the radiator disintegrated. 3 weeks later the new radiator tank sprung a leak and the radiator shop replaced it free. Three weeks later the same side drivers radiator tank failed again and the same radiator shop replaced it free again. The top radiator hose then started to come loose from the radiator consistently even is screwed down tightly I carried antifreeze and and a screwdriver for a quick fix on the run. I then took the car to the BMW dealer. They had the car for a week and could not find anything wrong no head gasket leaks, etc. I just drove the car home tonight from the dealer and the top radiator hose slide off the neck again. What the heck might be going on here? My wife is going to kill me if she has to pick me up stranded again.
December 16, 2010
Followup from the Pelican Staff: Sounds like the pressure is too high in your cooling system. I have seen this before with Porsches, but not BMWs. Perhaps you have air bubbles in your system that are causing this high pressure problem. I would rebleed the system 2-3 times and see if that improves the situation. - Wayne at Pelican Parts
January 6, 2011
Followup from the Pelican Staff: Another thing I forgot to mention previously - the radiator cap is responsible for maintaining and regulating the pressure of the cooling system. Too much pressure, and it's supposed to bleed off steam / coolant pressure. If you have the wrong radiator cap on there, or if it's stuck closed, then the higher pressure will start blowing out hoses and other components on the system. - Wayne at Pelican Parts
Comments: I have a e36 1.6cc 1999 plate and last time gets over heating, i check the pump and i replace the thermostat with second hand one, is to much steam coming out of bleeding and bowling to much. also in mornings the engine shakes and steam coming out from the exhoust the steam still there and afer. any help please
December 31, 2010
Followup from the Pelican Staff: If you have steam coming out of your tailpipe, then you have a problem with coolant getting into your exhaust combustion chamber in the cylinder head. It sounds like you probably have a head gasket issue - perhaps caused by an overheating issue. I would probably plan on removing the head to take a look at the condition. - Wayne at Pelican Parts
Comments: I have replaced the head gasket and water pump on my BMW 328i.
Now the water does not circulate. Please advice
December 31, 2010
Followup from the Pelican Staff: The only thing I can think of is that the wrong gasket might have been used. Some gaskets have different holes for coolant passages, and if you use the wrong gasket, then you won't get proper circulation of the coolant. - Wayne at Pelican Parts
Comments: Hi Wayne, I have two problems. I have 325tds and 318tds. With 318, during summer, it was overheating, then I changed waterpump a thermostat, but it was the same. I put it aside and took it out for a ride during winter. It is not overheating now, which seems kind of strange. Anyway, sometimes not always, the coolant gets out of of the container/filler during the ride underneath the screw top. Could the cold weather be the reason why it stays cool? Will it start overheating again during the summer?
And for my second problem. It is not actually a big problem, but with my 325, the problem is the opposite. It never stays warm, temperature is usually somewhere between blue and the middle, unless I rev it a bit.
December 23, 2010
Followup from the Pelican Staff: The coolant system is regulated by the radiator cap - pressure is released through the cap when it gets too high. If your cap is leaking, then it's time to get a new cap and that might fix the overheating problem. The pressure in the coolant system is required to keep the water / coolant from boiling over. If there is a leak, and the pressure is too low, then the coolant will boil off, and you will have overheating problems.
As for the 2nd car, if the temperature is between blue and medium, that might be normal. We don't have the tds diesel cars over here, so I'm not sure exactly at what temperature they are supposed to run. - Wayne at Pelican Parts
Comments: Hi, I have a 325i 94 recently changed the radiator and waterpump started it up today was ok for a bit then started to overheat, i noticed steam coming from around the theromstat housing and the right hose was very hot where as the left one was very cold, i had the theromstat changed about a year ago so i dont think its that and there are no obvios leaks under the car. what could be the problem? thanks
December 22, 2010
Followup from the Pelican Staff: Sounds like you might have an air bubble trapped in there. I would bleed the system again 4-5 times to make sure that you have all of your trapped air out. - Wayne at Pelican Parts
Comments: I have just replaced my water pump and coolant on my 318i 93 BMW .The mechanic has taken out the thermostat for summer. However later that evening the temp went to red very quickly and then the motor felt like it is about to pack it in .The top hose was very hot but the bottom hose remains luke warm. What could be the problem ??? I took it to the mechanics because this happened and nothing has changed.Please can you help ???
December 22, 2010
Followup from the Pelican Staff: First off, it's ridiculous that your mechanic removed the thermostat. The thermostat is there to allow the car to warm up to temperature quickly - without it, it will not get up to its proper temperature and will not run well. I would find another mechanic pronto. As for the overheating, it's obvious that your mechanic also doesn't know how to properly bleed the coolant system. I suspect there is a big air bubble in there. You need to have the system bled again and again until all of the air is completely out. - Wayne at Pelican Parts
Comments: I have a 2001 325xi which had a coolant reservoir failure 5 months ago, replaced with a new one. Next, the "service engine soon" light came on a few months later. BMW checked and said it was a stuck open thermostat so I had the housing replaced. About a week later, the reservoir I had replaced 5 months earlier failed. Why would these reservoirs keep failing? The engine temp has never gone above normal.
December 21, 2010
Followup from the Pelican Staff: It's impossible to know for sure, but I can take a guess. The radiator cap is what controls and regulates the pressure of the cooling system. If the cap is broken or stuck, then the pressure may get too high in the system, and that will cause odd things to happen like tank failures (because the pressure may be too high). I would replace the tank again and replace the cap at the same time. Also check to make sure that you have the proper cap installed - it's common to see the wrong installed, which may lead to higher pressures in the system. - Wayne at Pelican Parts
Comments: i have a 1993 525i. i replaced water pump and thermostat three months ago. it started to overheat on fri. sat i spent the afternoon taken it all apart got it taken apart water pump looked fine but i left thermostat off for now. and it still overheats. there is no movemant in radiator at high rpms. any ideas. car has 233,000
December 19, 2010
Followup from the Pelican Staff: I'm not sure how you can tell if there is no movement in the radiator? Either way, it sounds almost certain that you have a large air bubble trapped in the cooling system. I would bleed, and rebleed the system several times before tearing any more components apart. - Wayne at Pelican Parts
Comments: I seem to have a coolant leak from my bmw 320i which confuses me because it dont leak all the time! I recently replaced the radiator but sometimes there is a wet patch under my car and other times there isnt????? any help would be appreciated!
December 19, 2010
Followup from the Pelican Staff: Check the hoses - I recently had a leak on my Boxster that was similar - sometimes it would leak and sometimes not. Turned out the hoses were leaking from the middle layer inside the hose - very odd. Might also have something to do with the pressure in the system - make sure the cooling system is fully and properly bled. - Wayne at Pelican Parts
Comments: I have a 99 E36 328i. I had the radiator tank replaced after the plastic neck on the top of the radiator disintegrated. 3 weeks later the new radiator tank sprung a leak and the radiator shop replaced it free. Three weeks later the same side drivers radiator tank failed again and the same radiator shop replaced it free again. The top radiator hose then started to come loose from the radiator consistently even is screwed down tightly I carried antifreeze and and a screwdriver for a quick fix on the run. I then took the car to the BMW dealer. They had the car for a week and could not find anything wrong no head gasket leaks, etc. I just drove the car home tonight from the dealer and the top radiator hose slide off the neck again. What the heck might be going on here? My wife is going to kill me if she has to pick me up stranded again.
December 16, 2010
Followup from the Pelican Staff: Sounds like the pressure is too high in your cooling system. I have seen this before with Porsches, but not BMWs. Perhaps you have air bubbles in your system that are causing this high pressure problem. I would rebleed the system 2-3 times and see if that improves the situation. - Wayne at Pelican Parts
Comments: Hi there,recently bought a 2000 316i se,1.9ltr,lovely car.Sometimes when i drive,the temperature gauge races upto into the red,no light comes on,checked cooling system when it does this,isnt overheating,it will then drop down to normal working temperature.Could it be the temperature sensor is faulty?
December 8, 2010
Followup from the Pelican Staff: It could be the sensor, but it also could be that you have an air bubble in the cooling system. I would rebleed the system and see if that improves the situation. - Wayne at Pelican Parts
Comments: Hi Wayne.I have a 99 323is and presently no heat to inside cabin. The top radiator hose is nice and hot while the lower one is warm, the 3 hoses for the heater core nr firewall are barely warm and temp @ dash is always in the center. A few days ago I notice some steam coming out of the muffler here in miami.A year ago, I took the head cylinder down to replace the gasket,the machine shop showed me 2 cracks in the head and welded...They charge me $450..I put new wp/ thermostat etc..and she ran good for a year but just notice in the past 48hrs of the steam and no heat...HEEEELLP? it's in the 30's here in FL-WTH?!!
December 7, 2010
Followup from the Pelican Staff: Hmm, I would keep a close eye on your coolant, to see if you're having coolant loss. Sounds like you might be with the steam issue. There may be a bubble in your cooling system caused by a coolant leak of some type. I would recommend bleeding the cooling system first before you do anything else (well, actually check the coolant level first and maybe drive for a day or so to see if you're getting coolant loss). If there's no heat after that, then I would take a closer look at the heater valve - it may have failed. - Wayne at Pelican Parts
Comments: While driving my e36 328i sedan last night I started seeing a small amout of steam coming from under my hood. I pulled over and right before i turned it off, I heard a radiator hose pop. I hooked back the hose, went away for a couple hours to let it cool down, then I put some coolant mixture in. I drove back and after about 10 min of driving the needle shot to red and it popped again and I pulled over. While I was driving only cold air was coming out of the vents. Is this most likely an airlock in the cooling system from for the few seconds the car was running with the hose popped off?
December 2, 2010
Followup from the Pelican Staff: Yes, that's a good guess, you probably have an air bubble in the system. Bleed it a few times and then the temperature spiking problem should go away. - Wayne at Pelican Parts
Comments: i have a 97 bmw 316i 1.6 and on the heater control panal inside is shown just 32c and will not go up any higer. i have just got warm air coming out of vents .what could be wrong
November 30, 2010
Followup from the Pelican Staff: That's a European car, so it might be slightly different than the ones here in the states. I'm not 100% sure of which problem you are describing, but sometimes issues like these can be traced back to an external temperature sensor that has been damaged by road debris, or is just plain missing. - Wayne at Pelican Parts
Comments: Comments: Comments: Hi, I have a E30 316i with a M40 engine, just did a complete engine overhaul. Car runs ok but temp needle stays just above middle and stays there. Car has new radiator, thermostat, water pump. Any idea what the problem may be? November 9, 2010 Followup from the Pelican Staff: That actually sounds about normal. - Wayne at Pelican Par
Shouldnt needle be pointing halfwat, my needle is pointing 2 or 3 needles above half, although doesnt move from there. Waht would the symtoms be if there is a problem with the fan clutch? November 24, 2010 Followup from the Pelican Staff: Those gauges are notoriously inaccurate and cause a lot of people to needlessly worry. I would check actual engine temps with an infrared thermometer and see what they are in radiator and the hoses leading up to it. - Wayne at Pelican Parts
What are the normal operating temperatures?
November 26, 2010
Followup from the Pelican Staff: It depends upon which thermostat you put in your car. If you put in an 80 degree C thermostat for example, then you should be running that out of the thermostat and into the radiator (approximately). - Wayne at Pelican Parts
Comments: Comments: Hi, I have a E30 316i with a M40 engine, just did a complete engine overhaul. Car runs ok but temp needle stays just above middle and stays there. Car has new radiator, thermostat, water pump. Any idea what the problem may be? November 9, 2010 Followup from the Pelican Staff: That actually sounds about normal. - Wayne at Pelican Par
Shouldnt needle be pointing halfwat, my needle is pointing 2 or 3 needles above half, although doesnt move from there. Waht would the symtoms be if there is a problem with the fan clutch?
November 24, 2010
Followup from the Pelican Staff: Those gauges are notoriously inaccurate and cause a lot of people to needlessly worry. I would check actual engine temps with an infrared thermometer and see what they are in radiator and the hoses leading up to it. - Wayne at Pelican Parts
Comments: I have a '95 BMW 318i. The previous owner replaced the head, and once I got it running, it was overheating and had a leak from the thermostat housing. I got the leak fixed and installed a thermostatdidn't have one and it's still getting too hot. The electric fan is not coming on. At what point should it come on and could that be the problem?
November 23, 2010
Followup from the Pelican Staff: I would make sure that the system is completely bled of air and doesn't have any leaks. If the system is leaking, then it will allow pressure to release, and it will overheat. Also check the radiator to make sure that the coolant is getting to it properly, and being cooled.- Wayne at Pelican Parts
Comments: i have a bmw 316i se 2000 1.9 petrol that the cooling system is pressurising & the blowers are blowing cold. tried bleeding many times can anyone help?
November 16, 2010
Followup from the Pelican Staff: Sorry, I'm not really sure what you mean? - Wayne at Pelican Parts
Comments: Hi, I have a E30 316i with a M40 engine, just did a complete engine overhaul. Car runs ok but temp needle stays just above middle and stays there. Car has new radiator, thermostat, water pump. Any idea what the problem may be?
November 9, 2010
Followup from the Pelican Staff: That actually sounds about normal. - Wayne at Pelican Parts
Comments: Simple to read and very informative article, thanks.
November 6, 2010
Comments: Where is the thermostat located that everyone is discussing on the 2007 X3 and does anyone have pictures?
November 2, 2010
Followup from the Pelican Staff: The X3 has the same six cylinder as the E36 car in this article, so the thermostat should be under the same style cover (it may be black plastic though on the X3). - Wayne at Pelican Parts
Comments: I saw your comment on my applying 22 inch pounds to the bleed screw. I have an in-lb torque wrench that has a max of 50 in lb. I actually have about 4 torque So, yes I am sure that is all that was applied. BMW radiators tend to suck anyway, so it may be that the plastic is just brittle. It was fine before I tightened the bleed screw. I would also point out that the torque for the Radiator drain is 2.5nm or 22 inch lb. and that is a much larger diameter thread, so I still think 70 in lb is high for the bleed screw.
October 26, 2010
Followup from the Pelican Staff: Interesting feedback. Okay, in that case, then I typically recommend that people tighten up the screws very lightly, and then if it leaks, increase the tightness until it stops leaking. It may be that it was indeed old and brittle, and it's time had come? - Wayne at Pelican Parts
Comments: I tightened the radiator bleed screw to 2.5nm or 22 inch lb and it cracked my radiator at that point. Is there any fix, or am I stuck getting a new radiator The 70+ inch pounds you recommend seems way too high.
October 26, 2010
Followup from the Pelican Staff: Hi there. 22 inch-lbs is very little force. My six-year old can apply that. That's two pounds of force on a 12" socket, which is not measurable by any tool that I have. Are you sure you didn't accidentally apply ft-lbs (12X the force?). You can try gluing the radiator, but it may leak in the future, unfortunately. - Wayne at Pelican Parts
Comments: Hi - I have an E36 tourer 98 plate and have recently experienced intermittant overheating. Yesterday, the car overheated to such an extent that I lost all coolant from the undeside of the car. I put it into my local garage and they advised that the inlet hose was split and duly replaced it. On the way how it was fine for about an hour and then all of a sudden the temp guage went into the red and I started dumping coolant again but not through the pressure releif but through the underside of the car again. I also noticed that the car was fogging up inside a smeeling of coolant and the carpet is wet at the centre console - can you halp please!!
October 26, 2010
Followup from the Pelican Staff: There's another crack in there, probably behind the dash, near the hoses or heater valve that supplies hot coolant to the heater. The system with a leak will boil over and overheat. Your mechanic should have pressure tested the system to make sure there weren't any other leaks. I would bring it back to them, or maybe go somewhere else? - Wayne at Pelican Parts
Comments: Brilliant Pelican write up for coolant replen, thank you!!
October 20, 2010
Comments: I just had my mechanic replace my thermostat and he used Prestone Extended Life Any Make Any Model. I think he might have used tap water. Should I have it flushed and replaced with BMW coolant and distilled water or can I leave it till next year.
October 16, 2010
Comments: have a 2006 325 and check engine light will come on and a machanic checked and said needed to replace thermostat housing no over heat problems with the car any advise on what to do doesnt seem right
October 3, 2010
Followup from the Pelican Staff: That could be - those modern cars have an electronically controlled thermostat, so if the computer is outputting an error code related to that, then I would guess it might be an issue. - Wayne at Pelican Parts
Comments: hello thier Wayne, I have the common problem of my BMW overheating. My radiator hoses seem to build up with alot of pressure. Could you please help in solving my problem. And could it be a expensive blown head gasket? or is thier anything else you reccomend in doing first.
October 2, 2010
Followup from the Pelican Staff: If your hose is building up with pressure, then the water pump is probably pumping water into a clogged radiator. I would remove the radiator, and take it to a shop to have them inspect it. Or, simply just replace it with a new one. - Wayne at Pelican Parts
Comments: I recently bought a 1999 BMW 323i. Within two days it overheated and boiled the antifreeze out of the reserve tank. Had water pump, thermostat, and expansion tank replaced. I did attempt to bleed the sytem last night. Again today it boiled over. Both times I was driving the car hard. The heat did work last night through the middle ports in the cabin where before it only came though the floor port.
September 28, 2010
Comments: i recently changed the thermostat on my e36 318is and did a coolant flush since then my car struggles to start when its cold out could i have put too much coolant in?
September 27, 2010
Comments: Hi, i have a bmw 320sport 2003. i changed the expansion tank about a month ago as it was cracked and recently noticed that the water light in the dash keeps coming on. the 1st few times the light came on, i checked the water levels and it was half empty so refilled. took it to a garage but they couldnt see any leaks. then i noticed that whenever i put the heating on, thats when the water light comes on. if i dont put the heater on, then the water light doesnt come on. any ideas what is causing this?
September 27, 2010
Followup from the Pelican Staff: Well, you could have a leak in one of the hoses to your heater core. If you put the heater on, and let the car idle, do you see any coolant leaking out the bottom of the car? Or, you could just have some extra air in the system. The coolant system needs to be bled with the heater turned on - if it's not, then you might have some issues like these. - Wayne at Pelican Parts
Comments: Where should the needle of the temp guage be? Is it in the middle I have a 318ti
September 18, 2010
Followup from the Pelican Staff: In the middle sounds about right. It seems to be slightly different on every car. - Wayne at Pelican Parts
Comments: Hi I just replaced the radiator an the head gasket in my 318ti had the coolant added by me and my moms boyfriend who is a BMW mechanic and it was running good for about 30 miles then the car started to overheat again and leak antifreeze area the front of the transmission an I have no clue what it can be can u give any hints to what it can be
September 12, 2010
Followup from the Pelican Staff: Heater core maybe? There's a hose on the back of the head that needs to be reconnected, and it's easy to forget to attach it. However, the car probably wouldn't run at all with that disconnected, as it would spew coolant all over the place. Still, maybe the hose has come loose? Track down the leak and then bleed the system again is my suggestion. - Wayne at Pelican Parts
Comments: Hi there. Recently purchased a 97 316i. For the past few weeks I've noticed that the thermostat goes into the red on short drives. I've checked for any leaks but can't find any and the coolant level is correct. Could it be that I need to bleed the system?
September 8, 2010
Followup from the Pelican Staff: Yes, I would indeed suggest bleeding the system a few more times - might be a trapped air bubble. - Wayne at Pelican Parts
Comments: Hello I own a 1991 525i BMW,never overheated before,today coolant temp light came on,and overheated,topped of coolant,no leaks are present,drove around the block,light comes on again and temp guage is in the red,what could be the problem?Thanks
September 2, 2010
Followup from the Pelican Staff: Could be a coolant leak? Fill the system, and then bleed it several times, topping it off as you go. Then check the coolant levels. You may have a crack in a coolant hose that you can't easily see either, and that may be introducing air into the system (which causes air bubbles and overheating). - Wayne at Pelican Parts
Comments: I have a 2006 330 ci 69k miles and the coolant is leaking. Pressure tests have not shown how. The coolant light comes on and is off when the car warms up. Drove 10 miles and engine started to smell like it was overheating but the temp gauge was normal. I suspect a faulty head gasket, valve cover, or spark plug. What else should I make sure the mechanic is testing?
August 31, 2010
Followup from the Pelican Staff: If coolant is disappearing, but you can't see where, then it's almost always leaking past the head gasket and coming out of the exhaust as steam. - Wayne at Pelican Parts
Comments: Hey i have a 1993 325i and it never overheats but whenever i top off the coolant it always goes back down to halfway in the reservoir. Only today i noticed hissing coming from under the hood after a 15 min drive. The sound seemed to be coming from the engine but i couldnt pinpoint where. My valve cover gasket has been leaking oil a little bit but i dont think thats it. Still the temperature gauge stays at halfway all the time. I hope its not a headgasket problem. Thanks for your help
August 27, 2010
Followup from the Pelican Staff: There is an overflow hose that will dump out excess coolant if you overfill it. I suspect that your car is full and is dumping the coolant it doesn't need. If you don't have an overheating problem, and the coolant tank level is in the middle, then you should be fine. As the car heats and cools, the levels in the container will tend to move up and down. - Wayne at Pelican Parts
Comments: my 1994 bmw 325i gets to and maintains running temp at idle but after approx. a minute or two of driving the temp climbs to red unless i stop and let it idle. the top radiator hose gets hot and the bottom stays cold. there are no coolant leaks. the heater does not heat at all. i completely flushed the whole cooling system and refilled it. i have bled the air from the system 3 or 4 times and all it has done is made it go about 100 feet farther down the road before it overheats after each bleed.
August 17, 2010
Followup from the Pelican Staff: Odd that the heater doesn't work - did you turn the heat on when you bled the system? There seems to be some serious air trapped in there, maybe. Did you happen to check the condition of the radiator? Did you check the thermostat in a pot of water to see if it's opening properly and all the way? - Wayne at Pelican Parts
Comments: My 99 BMW 328i overheats and spews coolant from resevoir tank after about 30 minutes and I have no heat coming out of the vents it is just luke warm. Can you give me any suggestions on where to start.
August 8, 2010
Followup from the Pelican Staff: Bleed the system as detailed in the instructions in this article. Make sure that you have the heater on - it sounds like there are some air bubbbles in there. - Wayne at Pelican Parts
Comments: I have a 99 328i and after changing plugs after a bad idle I noticed coolant inside the 5th and 6th spark plug hole under the coil. What could cause this ? valve cover gasket or head gasket ?
July 30, 2010
Followup from the Pelican Staff: Coolant inside the spark plug holes would most likely be a head gasket problem, although I haven't personally seen this happen before. Oil in there would indicate a faulty valve cover gasket. - Wayne at Pelican Parts
Comments: Just a small piece of additional info... I used a ph teststrip last night and found the glycol rating still at 50% and the ph value around 8. I presume I havent put enough miles on the current coolant for it to degrade significantly despite the 5 yrs its been in there.
July 25, 2010
Followup from the Pelican Staff: If your coolant tests okay, then it's probabaly still good for a while. I would only use distilled water, as tap water typically contains those limestone type minerals that tend to build up and adhere to the aluminium components in the car. - Wayne at Pelican Parts
Comments: I have 2 questions.. First, Ive only driven about 15k miles since my last coolant change, however, its taken me about 5 yrs to drive this distance... The coolant strength is still in the 'ideal' gauge according to the gauge I used to check it.. Do I need to do a change based on years, or can I adhere to the mileage guideline since I drive only about 3k miles per year these days?
Second, is it preferable to mix the bmw coolant with Distilled water, or is tap water that is not 'hard' sufficient?
July 24, 2010
Comments: I just had a cooling system failure in my 2001 BMW 325xi, the coolant sign was keep comming up on an irregular basis but the car was running fine, when i checked the coolant, the reservoir was full, suddenly one day when driving back to home the temprature sign shoot up to the red zone leading the car to stop right in the middle of the road, thx God no one hit me and i am alive.
I drove so many cars for so long and none of such issue ever happened, but it seems to be happening only in the BMWs, I am amazed how insincere they were in their manufacturing and design- worrying how these cars are sold in the US market without leading to any class action lawsuit against them.
Coming to the point, the repair shop found that the car had faulty Thermostate & coolant expander tank also had a crack because of coolant refill post engine overheating.
Even after the repair- the car seems to overheat as I can feel with the variation in the cabin air temprature and this incident seems to re-occur soon.
July 14, 2010
Followup from the Pelican Staff: I would make sure that you rebleed the system 3-4 times. It takes this many times to get all of the air fully out of the system. - Wayne at Pelican Parts
I have an overheating problem with my car.It started with stuck thermostat which i replaced.Overheating still persists and surprisingly,the upper hose is always very hot and the lower hose very cold even after driving long hours.,My engine is a 3'18i 2001 model.
July 5, 2010
Followup from the Pelican Staff: First thing I would try is re-bleeding the system again. Air bubbles can get in there quite easily and cause overheating problems. You might want to take a closer look at the radiator too, although hot / cold is about typical for the radiator. - Wayne at Pelican Parts
Comments: Really really useful site just a pity i hadnt seen this before spending a fortune on parts for the my e46 2000 BMW. Its driving normal for maybe 10mins before rapidly overheating to an extent to where the thermometer gauge goes right to the end off the red. I changed the water pump, removed the thermostat incase it was sticking, changed the cap on the rediator reservoir, replaced the hose pipe from the engine to the rad n bled it... I was told theres a second outlet where uv to bleed but cant find it?? Do you think the head is gone...and if so would i be better off getting the head skimmed or a replacement second hand engine? Many thanks
July 5, 2010
Followup from the Pelican Staff: Before you give up, bleed the system, then rebleed it, and then bleed it again. Let it run out of the radiator for quite some time. These cars have troublesome cooling systems that are difficult to bleed, most of these problems are caused by air pockets in the system that can cause spot overheating. - Wayne at Pelican Parts
Comments: CAN ANY OF YOU PEOPLE HELP I NEED THE NAME OF THE BIG COG AT THE BOTTOM FROUT PART OFTHE ENGINE OF MY BMW 3SERIES 320 I HAVE BEEN TOLD ITS SLIPPING WHICH IS MAKING A TINKING NOISE WHEN ENGINE IS RUNNING
July 4, 2010
Followup from the Pelican Staff: You must be referring to the harmonic balancer? - Wayne at Pelican Parts
Comments: I just replaced the radiator after it kept leaking on the side where water is fed from the engine, it would steam all over and would drive for 10 minutes and need a garage for water topup. Obviously by now my cooland is simply water. This morning I added 3 litres of antifreeze but found that it had started leaking again, this time it was steaming through a crack it ad caused on the short pipe with the bleeder, the one next to thermostat. I have learnt aboe about the proper way to drain and filling of new coolant, is this the solution and he the replacement of the cracked pipe? The car recently never heated inside and the settings stayed on high, but it would overheat now and then as 'water' drained out as I drove. To prepare coolant: should I mix 50/50 separated and fill up with a readymix solution while following the bleeding instructions given?
July 2, 2010
Followup from the Pelican Staff: Sure, yes, it sounds like you're on the right track. Premix and fill, and then you can top off with premixed, or put some of your mix back into one of the bottles. - Wayne at Pelican Parts
Comments: I recently replaced the radiator, water pump, and thermostat on 97 M3. Followed your directions and everything went smoothly. My question is about the thermostat. I installed the 88C instead of the 92C. Hoping to run just a little cooler. Should I also replace the aux fan switch so that they match? Thanks.
July 1, 2010
Followup from the Pelican Staff: Good question. For maximum cooling, yes, the fan needs to go on a bit earlier if the thermostat is also opening up sooner. So, the installation of a lower-temp switch is indeed typically a good idea. - Wayne at Pelican Parts
Comments: i have a 1997 bmw 328is, i recently replaced the fan, and the radiator and filled it up with new, coolant but its still overheating and and its leaking oil when it starts running!,could it be the head gasket, because when i look underneath it, it looks like its coming from the side of the motor
June 29, 2010
Followup from the Pelican Staff: Bleed the system 4-5 times and see if it's still overheating. The head gasket might leak from the head/case interface, but that is highly unlikely. It might be the valve cover gasket, which would be unrelated to the overheating issue. - Wayne at Pelican Parts
Comments: I have a coolant leak but I cannot locate it. I have all new cooling system parts on my 98 328is. It idles rough in the morning for like 30 secs. and after 30 mins of driving, i can smell coolant coming from the ac vents and its disgusting. i dont think its a hg otherwise my car will smoke and if i open my hood i see dry coolant on the engine and its like coolant has been touching the fan and the fan shoots it to random places. any ideas? thanks in advance.
June 19, 2010
Followup from the Pelican Staff: You need to look closer when the engine is running to see if you can find the source of the coolant. It's probably blowing around the engine compartment and then getting sucked into your fresh air vents. - Wayne at Pelican Parts
Comments: My 318 ci coolant level sensor keeps coming on and then going off....Ive checked the coolant level on each occasion and its fine could the sensor be damaged?
June 18, 2010
Followup from the Pelican Staff: Yes, the sensor has a habit of breaking too. I would replace it and see if the problem goes away. Also check to make sure the electrical connection to the sensor is solid and firm. Also, coolant can leak out of the o-ring in the bottom of the sensor and then corrode the contacts on the sensor. Sometimes just replacing the o-ring and cleaning the contacts with a wire brush will fix the problem. - Wayne at Pelican Parts
Comments: regarding the 328i over heat. Turns out it was the water pump. Took it off to check it and impeller had cracked. Was hardly turning at all. Replaced and all seems well. Thanks for your reply.
June 12, 2010
Comments: 1995 328i Over heat. Have put in new thermostat and is working. Both pipes either side of it get hot. The problem is that staionary the car will never overheat and you dont get hot air from heater but, When you go out and put your foot down the temp goes right up to the red and the light comes on. As soon as you turn on the heater the gauge comes back down to normal temp. Then I have left the car idling and the temp stays normal and the hotair stops blowing through!!! Any ideas please??? I thinkit could have something to do with heat control valve maybe? Dont know.
June 11, 2010
Followup from the Pelican Staff: Sounds like you have some air bubbles trapped in your heater valve or something similar to that. Bleed the system 3-4 more times. If that doesn't work, then empty the coolant and try again. When the temps spike like that immediately and quick, it's almost always an air bubble of some type. - Wayne at Pelican Parts
Comments: I have that issue with the steam coming out the tail. I have a 98 328i.When i try to start the car after sitting all night, it feels like its flooded and takes awhile to actually turn over. then it idles really rough for a min till i rev up the motor.then it seems to run fine.though i am having to add coolant every day or two.Every thing on it is new,i mean everything,so my thinkin is HG.My mech guy says theres a leak in one of the cylinders.there is definitly a sweet smell coming out of the tail pipe.Is there a simple way like Bars leaks 1 step gasket fix.Or will I do more harm than good.I really dont have or want to spend $1200 on a new HG.Any info would be greatly appreciated.thank you.
June 10, 2010
Followup from the Pelican Staff: Yup, all signs point to a head gasket failure. I have a tech article in this section on it - it's complicated, but doable in your garage... - Wayne at Pelican Parts
Comments: there so many board on bmw's that i think the easiest and most effective fix i could do for my 1998 328is, is selling it!
June 10, 2010
Comments: On a BMW 328i'97 replacing a hose I noticed that the bottom radiator hose connects to a metal pipe that makes a T junction branching to the right to the heater and to the left to what could be the waterpump, this pipe is very corroded on the outside and may need replacement. It seems like the whole injection system has to be removed to access this pipe, and looks solidly connected to the left - Can it be done DIY ?.
May 25, 2010
Followup from the Pelican Staff: You'd have to send or post a photo, as I'm not 100% sure which pipe you're referring to? - Wayne at Pelican Parts
Comments: My 3.28is has an external coolant leak that is noticeable as a drip from under the crankshaft on the timing chain side of the engine block. It drips only when the car has cooled off. I recenly replaced both the thermostat and the thermostat housing. I have inspected the water pump. The leak was due to the thermostat and housing. I've taken it apart and resealed the gasket, but the leak is still there! Any advice? Is it possible that the thermostat seal o-ring is not working, even though it is new?
May 13, 2010
Followup from the Pelican Staff: It's possible that your seal is not sealing properly due to electrolysis damage to the head (see photos in the head gasket replacement article). I recommend using some sealant in addition to the new seal to help seal up this area. - Wayne at Pelican Parts
Comments: i just bought a bmw 520i station wagon it overheats from time to time each time i blead the air out of the system it seems to be okay, but when ever i drive the car with the aircondition on the temperature rises so high and when i put offthe a/c it goes down almost immediately, when parked i notice there is a leakage from underneath of the radiato, what is the problem thanks . tunji
May 4, 2010
Followup from the Pelican Staff: Sounds like you may have an air leak in your system. If there is a leak, then the coolant won't be able to superheat without boiling off. Pressure check your cooling system and/or check to see where that leak is coming from - it's probably the cause of your pressure drop and overheating. - Wayne at Pelican Parts
Comments: Thank you for your response Pelican staff..it was really helpful..now i have a problem..i broke one of the screwsthe one on top for the thermostat housing and now i can hear an air whistle coming out of it...I new i was gonna have problems because of it but i just wondering if i can do something to fix this myself. I know its gonna be expensive to have somebody remove the broken screw any ideas?? use some sort of silicone maybe??? and is it normal that if i have the car running for a while without the expansion tank cap on the antifreeze starts coming out and its overheating...?? I was just trying to pour antifreeze in the radiator but its not going into the engine I guess.. plz help
Comments: After doing extensive research on coolants, there seems to be nothing particularly special about the product directly available from BMW. The p-glycol is a bit more expensive, but less toxic and as the article pointed out doesn't provide as good low temperature protection. The e-glycol Prestone product is phosphate/nitrate/borate/silicate free and clearly suitable for any aluminum based engine and/or radiator which may contain other metals or plastics. As to the phosphate issue, that seems to only be a problem if hard water is used. With distilled water there should be no problem. And while there have been some comments about distilled water tending to absorb CO2 and becoming acidic, this mild acidity would be more than compensated for by the coolant basic additives.
With regard to the thermostat, is the rotational orientation of thermostat primarily important for smooth coolant flow over the two supporting prongs going to the center ? It would seem the optimal orientation would be to have a line between the prongs parallel to the coolant flow. Is this correct? Or does the orientation have something to do with the thermal operation of the thermostat?
April 21, 2010
Comments: I have a BMW E46 316i 2000 which has a new rad,expansion tank capand thermostat.The car drives fine temp stays normal throughout any driving but when i stop and turn off the engine the coolant bubbles up under pressure though the cap. have you any ideas.
April 19, 2010
Comments: recently put a new hedder tank in but now the bottom pipe is not getting hot does anyone know why?
April 16, 2010
Comments: 2000 528i all wheel drive. It has been over heating and lost power on the highway. Had it towed home and when I fill it with coolant and turn on the key it purges the water out in the front of the engine somewhere and will not start. Any suggestions?
April 4, 2010
Comments: my 2002 525i radiator expansion tank has a leak, I ordered a new one, but couldn't figure out how to remove the old one from the radiator cover, I was wonder if I have to remove the fan and radiator cover before replacing a simple expansion tank.. I also have trouble locating fuel filter for this car.. can you help guiding me to the right direction.. Thanks..
April 2, 2010
Comments: I think that it saw this too late. I have an 1997 E36 M3 that started gushing out coolant yesterday as I stopped at a gas station for fill-up. I noticed steam coming out of engine bay. My mechanic says that there is a hole in timing cover and gave me a 12 hr labor estimate in addition to cost of replacement parts, but the BMW guys disagree saying that if there was a hole in timing case, then oil will spurt out and not coolant. Who is right and do you have any ideas?
March 24, 2010
Comments: I had the engine running on my car for 20mins and the bottom pipe was still stone cold, would that be the thermostat? or is that normal? the day before i had low collant but i topped it up, i have colant leaking because my heater matrix pipes are weeping.
March 10, 2010
Comments: Hi it is strange,while my 1998 BMW 520i touring is idle with the nose of the car high would run for hours and not overheating.
If driving,the needle goes up within 500 yards driving.Any idea?Thanks
February 22, 2010
Comments: Hi Wayne,
I have a '93 318is manual trans leaking coolant with the engine off. It is coming out in a steady stream from behind the a/c pump bracket. The radiator brackets, water pump, and thermostat housing appears dry. The leak is big and just pours off the a/c aluminum mounting bracket.
Any ideas? Where is the weep hole for the water pump?
February 19, 2010
Comments: Hi there late last year done a cooling system overhaul on my 318ti E36 M44 motor BMW this included hoses,water pump,thermostat and just recently the radiator,all parts ex pelican partsand Im still still having over heating probs, Ive filled the system as per the tech page alls well idling in drive way,take it for a run and the coolant blows out the radiator capnew cap as wellany suggestions. ready to burn car
February 5, 2010
Comments: One the 1995 BMW 328is, access to the drain plug on the engine block is obstructed by the O2 sensor in the header. Is there another drain plug that can be used?
February 1, 2010
Comments: Hi, could i know what is the appropriate pressure number for radiator cap of e36 318i 1996... is it 140 or 200?
January 16, 2010
Comments: Does anyone know if i need to remove the fan housing to remove the coolant expansion tank? I have a '98 328i.
January 14, 2010
Comments: Check engine coolant light comes on briefly when starting or shutting off engine once it reaches normal operating temperature. No over heating and coolant level is normal. Changed water pump and thermostat and bled coolant correctly. No leaks, normal operating temp, just this irritating check coolant warning. Since the cooling system is operating normally. Should I consider replacing float sensor in the expansion tank? Second request.
January 12, 2010
Comments: OK, I admit it, I was bad my mechanic told me so and I used a leak sealer to buy some time on the inevitable valley gasket replacement on my 2001 540i. Now I want to do a very thorough flush of the system by running water through it for a while before having this job done to clear out the gunk that the sealer introduced to my system. Once I have drained and recycled the existing coolant, my plan is to: 1 connect a garden hose to let the water in and 2 disconnect a hose or open a drain plug to let it flow through the entire system before exiting. My thoughts are to let this flow continue for about a half hour or so to make sure it is as clean as possible. What would be the best entry and exit points for this flow? Any thoughts? Should I use an additive to help remove the gunk? Should I use warm water? Any photos or diagrams you could provide would be greatly appreciated. Thanks in advance - you guys run a great site!
January 11, 2010
Comments: I used a 20" + 6" + wobbly head + jointed not sure of technical name adapter + 19" socket to remove engine plug along with an inexpensive plastic cement mixing tray available at HD or Lowes to drain the coolant from my block. Didn't get a drop on me. Amazingly, my Haynes manual didn't mention draining the block!! Time to purchase your 101...
January 11, 2010
Comments: Hi Wayne, I have a problem with my 1997 BMW Z3 1.9 owned from new with 46000 miles on clock with full bmw service history. Just done my first work on it and changed the water pump bleeded system and ran ok on normal temp. When checking for more air and topping up I found that the top hose to rad VERY hot and lower hose Very cold? I was not happy with this so put in a new thermostat. Followed all bleeding again but same problem? Hot top hose and cold lower hose with fan heater in car blowing hot then cold when set on hot?
To me this looks like I still have air in system? followed all bleeding suggestions but still have same problem. Are you able to advise me on what to do as I don't want to use car and cause a larger problem like overheating and blowing head gasget etc.
December 28, 2009
Comments: Hey Wayne, give this a shot!!!
I devised a simpler,cleaner, and more effective way to bleed a E36 or others with built in expansion tank.
Go to your favorite hardware store, and buy about 1-2 feet of clear vinyl tubing 1/4" ID x 3/8" OD...this tubing is just the right size to fit down in the bleed hole..to aid in the release of air, use some diagnoal cutters Dikes or a razor and make a little notch in the tubing about 3/16" x 3/16" shove the tubing down the bleeder hole, with the notch facing the driver side of the radiator. Fill radiator to cold mark when cold.
Put on some gloves, because the tube gets hot enough to be uncomfortable to bare fingers, safety glasses are a good idea too. Keep a clean jug nearby...you'll need that to capture fluid as it expands. If you can. slightly elevate front of car on ramps or something just to get the bleeder a little higher. Have someone competent start the car, turn heat on high. Let engine run and heat up tube in bleeder, rad cap off You will start to see bubbles come up the tubing. You can divert the tubing right back into the overflow tank....as coolant heats and expands the coolant level will rise, so divert some coolant into your clean jug, to avoid a mess.
As you hold the tube and watch for bubbles, have a competent person hold the engine at about 1500 rpms, that should be enough to pump coolant though the tubing, and back into the expansion tank or jug if necessary. You will be holding and watching this tube for a while probably 5-10 minutes. Adjust engine rpms so that coolant moves slowly through the tube 1500-2500 rpm As bubbles come out of the system, the coolant level will drop, so just add a little to the tank from your jug....eventually, there will be just a steam of tiny little bubbles in the tube, which may be turbulence...use your judgment as to when you are done....when done, drop rpms to idle, the coolant should back down the tube. Install bleeder screw, then the cap BEFORE SHUTTING DOWN THE ENGINE. If you mech fan is deleted, you may want to put a box fan in front of your radiator just to aid in preventing a boilover. When you removing the tubing, it will have little identions from the threads, as the tube gets hot it softens, and expand from the water pressure, making a tight seal.
December 26, 2009
Comments: Changed water pump on 95 525i M50 engine. Refilled with new coolant and bled the system. Operating temp is normal, no leaks. When starting the engine or shutting it off the check coolant warning comes on and the goes off. The fluid level in the expansion tank is at normal level. Since the fluid level in the expansion tank is at normal, could the problem be caused by a faulty float sensor in the expansion tank?
December 20, 2009
Comments: i have a 2000 323ci bmw an I'm having a cooling problem. I have change fan cluch,water pump cap,and thermostat.my temp is still reaching hot what should i do now.
December 19, 2009
Followup from the Pelican Staff: Bleed, bleed, bleed the system. Usually strange cooling problems are caused by air pockets inside the cooling system. Make sure the heater is on full blast when you bleed too. - Wayne at Pelican Parts
Comments: I have the same problem that summermoon describes 4 okt 2009. with my bmw 318i1991,the cooling fluid leaks through the upper part of my radiator. The fluid is very brown from rust and inside the car it smells like something is burned. would it help if I just pour bar's leaks inside?
December 18, 2009
Followup from the Pelican Staff: Hmm, I guess you could try that, but I would suspect that would only be a very short-term solution. - Wayne at Pelican Parts
Comments: Was able to get a m45 Torx socket and it solved the problem I had in releasing the tensioner. Everything is back together and running smoothly. Thanks
December 16, 2009
Comments: When removing tension to remove belts on water pump change I stripped the insert on the tensioner. Replaced water pump but now can't ratchet the tensioner to reinstall belt. Any thoughts, and will I have to have a professional replace tensioner. 1995 525i M50 engine
December 15, 2009
Followup from the Pelican Staff: The belt tensioner? It would guess that you'll have to re-tap the block with a larger thread, which is not easy to do. You might have to take out the radiator to gain some access room. - Wayne at Pelican Parts
Comments: I have a rusty coloured fluid spitting out of my 1992 316i touring and was wondering if this could be causing or adding to the problem. Thankyou. Tim.
December 15, 2009
Followup from the Pelican Staff: That sounds pretty terrible. I would indeed try a coolant flush to start. - Wayne at Pelican Parts
Comments: Recently had water leak in vacinity of the water pump and noticed a puddle of rusty water on garage floor. Engine developed a metal on metal sound and I assume the water pump went bad. Also when turning on or off the engine after reaching operating temp the check coolant light comes on but not consistently. Engine temp is normal and when I check reservor the coolant level is normal Any thoughts? Have ordered a new water pump from PelicanParts but haven't installed it yet until I talked to you. Plan on installing water pump and flushing system with new coolant hoping this will solve the problem. At a loss in figuring out why check coolant light comes on. Could it be a faulty sensor in the reservor and if so what is the best way to change it?
December 12, 2009
Followup from the Pelican Staff: You're probably low on coolant from the leak. Replace the pump, the thermostat, and then flush the entire system, and that should help improve the situation. - Wayne at Pelican Parts
Comments: I don't know what kind of coolant the previous owner put in my 96 328is and was wondering what you thought of the Prestone 50/50 long life coolant which is phosphate,silicate,and borate free as a replacment Vs the BMW coolant. Since if I need more the Prestone would be readily avaliable. Whereas if i used the BMW coolant I would have to order it. Thanks
December 10, 2009
Followup from the Pelican Staff: I've used both the Prestone and the BMW coolant. Nothing beats the factory coolant, but the Prestone stuff shouldn't hurt the car. I typically have some extra BMW coolant on the shelf just to top off if necessary. - Wayne at Pelican Parts
Comments: BMW 528i 1997. I did bleed many times, when engine was hot.But i didnt see that fluid spills out, only fluid with air as a foam for a long time.What is wrong?
December 5, 2009
Followup from the Pelican Staff: Your system might be low on coolant, or you have a leak somewhere that is causing pressure to be dropped. Fluid should come out of the top if there is enough coolant in the system. - Wayne at Pelican Parts
Comments: I just changed out the thermostat and water pump on a 2000 328i. I bled the system and tested the car. It does not overheat, however, I checked the lower radiator hose and it was not hot. Should I be concerned?
December 1, 2009
Followup from the Pelican Staff: Nope, if it's running well and is operating at it's normal temperature, it will only use the front radiator when it needs to (via the thermostat). - Wayne at Pelican Parts
Comments: Just done a cooling system overhaul on my E36,everything bar the radiator,filled the system as per instruction but still overheating,noticed that thermo fan not comming in when temp is reached,is this the norm
November 24, 2009
Comments: Can you please give more detail on how to get to the drain plug on the engine block without jacking it up.
November 23, 2009
Comments: my 1992 325is is over heating.i changed the thermostat.it is still over heating.what could it be.
November 22, 2009
Comments: a 1991 325i,i noticed that the tempareture pointer guage is on red when i turn on the ignition without starting the car,,, i did replace the coolant sensor but no change
November 18, 2009
Comments: hi can you help me, i have a e36 bmw 316 compact 99 1.9, i am loosing coolant sometimes and i get a puddle at the front of the car on the right hand side, also the temperature in traffic gets up to the middle but on a run it will drop down towards the blue,is that normal? any ideas?
November 12, 2009
Comments: Is battery water the same as distilled water, and should I purchase the typical bottled battery water for replacing the fluid?
I bought the 1,500 ml BWM antifreeze. Do I pour in every drop 1,500 ml of antifreeze into my E46 expansion tank and not into the radiator? Im not sure what do you mean by 50/50 mixture, mine is 4-cylinder thus i will need 7 quarts or 6,624.47 ml of distilled water vs. 1,500 ml antifreeze?
November 10, 2009
Followup from the Pelican Staff: The BMW antifreeze should have some notes on the back as to whether it's concentrated or not. If it is, then add 50% coolant and 50% distilled water. On your E46, it's not possible to pour anything into the radiator, it all goes into the expansion tank. - Wayne at Pelican Parts
Comments: i have a 2003 330i i had a leaky upper radiator hose the clamp broke i replaced it then my car would overheat while idling after driving? when i filled it i just poured the coolent in the tank ?? is it that criticle to bleed these?? the lower radiator hose is stone cold and there is no heat???
October 29, 2009
Comments: Hi, I have a 2001, 320CI, the coolant low warning light comes on the dashboard intermittently but when the car is cool and I check the level it looks fine. Have you come across this before ?
October 24, 2009
Followup from the Pelican Staff: The levels will go up and down depending upon how the car is driving. I would probably add a little bit more coolant. If it continues then you might have some dirty or debris on the sensor inside the coolant reservoir tank, and I would probably replace the sensor. - Wayne at Pelican Parts
Comments: Hi, very nice site the best in yrs.
Need some help pls, my 97 328i 128.000 mls.is overheting and the auxiiary fan does not ran when in idle or when overheats to almost red, I did replace temperature sensor o engine block no change, I remove the termostat and is like new, I tested the fan and works when I acivate the relay manually, I activated the fan manually to see if temp, will lower, nope still temperature rise no change, need help pls.
October 23, 2009
Followup from the Pelican Staff: That's odd, you've checked both things that fail 99% of the time. On your car, I believe there is another temp sensor located in the lower radiator hose (can't recall exactly, as my E36 3-Series) didn't have that. This sensor may be the one that controls the fan - I believe it's that way on the 5-Series six-cylinder cars. - Wayne at Pelican Parts
Comments: Thanks for the detailed information about coolant changes. Excellent article. My question is: I replaced my water pump and thermostat in my '96 328is, and drained coolant from the lower radiator hose and water pump openings probably 1.8 gal of coolant came out. I didn't remove the engine coolant drain plug because it is difficult to access. It originally had green coolant in it from a previous owner, and I just topped off with a 50/50 mix of BMW blue. I assume there was still about 0.9 gal of the green coolant remaining in the block. Is it harmful to mix the two coolants? Should I drain it all back out and replace with BMW blue?
October 12, 2009
Followup from the Pelican Staff: It's not super-great, but I wouldn't terribly worry about it. I would change the coolant again in 2-3 years to freshen it up. - Wayne at Pelican Parts
Comments: can you give me a walk through on how to bleed this cooling system,,2001 325i,,i'm assuming it's not like the conventional chevy...
October 4, 2009
Followup from the Pelican Staff: Just follow the instructions above - open the screw when the car is running, with the heater on, until fluid spills out. Drive the car, let it cool down and then repeat as necessary. - Wayne at Pelican Parts
Comments: Hi, I have 1997 E36 318i Convertible that is loosing coolant. However its fine when running, nothing comes out. But as soon as it cools down it all dissipates and I can't see where its coming out. If I refill and leave over night its empty the next morning but no puddles under the car!! Its only done 69k miles.
Some suggestions as its a 55 miles trip to the nearest competent garage and 3 hour bus trip back home
October 4, 2009
Followup from the Pelican Staff: It's probably coming out of the tailpipe as steam. When you refill it up, it's then disappearing into the engine block. The coolant has to be going somewhere - that's the only real place it could be. - Wayne at Pelican Parts
Comments: a 2001 325i, i had the water pump grenade on me,,,i did replace the water pump, took it out for a test drive and it started to reach the red zone on the gauge, felt the upper rad hose and it wasn't really hot to the touch and squessing it didn't feel like there was any water in it,,took the thermostat housing off and noticed the thermostat was in the closed position,,,i'm thinking thermostat problem??? any ideas ??? thx
October 3, 2009
Followup from the Pelican Staff: Could be, but I would suggest that you bleed the system a few more times before replacing the thermostat. - Wayne at Pelican Parts
Comments: I have a BMW 07 335 and I would like to flush the coolant. Then engine compartment is extremely tight! I can not find the block coolant drain plug. Can you help?
October 2, 2009
Followup from the Pelican Staff: Sorry, I haven't worked on anything that new. I'd ask in the forums, as someone might have a photo for you. The coolant plug sometimes blends into the block and may not be 100% obvious. - Wayne at Pelican Parts
Comments: Wayne, yes the fan does turn. I will look in the electrical sectin like you stated. I was thinking the thermostat. Any wat to verify that?
September 29, 2009
Followup from the Pelican Staff: Yes, check the temperature of the upper and lower radiator hoses when the car is warm. They should be hot to the touch, which means that the thermostat is opening properly. - Wayne at Pelican Parts
Comments: hi there my car overheated last week due to my fan not kickng in as soon as i saw the needle hit red i switched off right away got it all sorted now but a few days later notced a bit of yellow cream on my filler cap know this can be common on the bm 330i e46 i do only go short distance so cud it be condonsation?
September 25, 2009
Followup from the Pelican Staff: Hmm, that's bad news and not normal. In all likelihood your head gasket is blown and will need to be repaired. The *exact* same thing happened to my wife's car - overheated and then the oil turned creamy. - Wayne at Pelican Parts
Comments: 1992 525i m50, Is it necessary to install the expansion tank cap hot or cold? On a cold engine the resevior is topped off but after driving a few times I get a low coolant message after removeing the resevior cap the coolant gurgles back into the resevior tank and the level returnes to normal?
September 22, 2009
Followup from the Pelican Staff: It sounds like you're low on coolant - removing the cap at hot or cold shouldn't make a difference. You need to fill the car, bleed it, drive it a bit, and then refill / top off and bleed again as necessary. There will often be air bubbles in the system that can be difficult to get out. - Wayne at Pelican Parts
Comments: hello i have a 730i bmw that at the mo isnt happy i have just ghanged thermostat and i am having differcultys with cooling system it seems to be air locked all the time even when i have done the way ive been told i fear that one of the heads has gone and yet no tell tale signs a freind says that the 7 is very hard to bleed and that at bm them selves they do it with graverty a long cylinder srcews on the header tank and it forces the air out is this true
September 21, 2009
Followup from the Pelican Staff: Sounds indeed like a bubble in the system. If you think you're having difficulty bleeding the system, then it might be wise to have a dealer or shop do it, whose done this procedure before. I'm personally not familiar enough with the 730 engine to be terribly useful. - Wayne at Pelican Parts
Comments: 03 330i today i tried to do coolant overhaul, it has been 2 months i had a expansion tank leak, today i changed expansion tank upper hose. i drain to radiator but i couldn't find 2nd drain screw! and i couldn't drain motor coolant because i couldn't open motor drain screw. Lower hose new one leaked from sensor so bad. i have to put the old one back.take a drive car drive ok and leak stop but there was just little drips,
September 10, 2009
Comments: when i opened up my radiator cap the color of the coolant was a light gray. im in the process of replacing my water pump which has just died, two question, 1- why is the coolant gray? and 2- how do i hold the pulley to loosen the nut to get pulley off of front of water pump
September 10, 2009
My M3 looks like it is one with a separate, external expansion tank are self-bleeding.What is the procedure for bleeding these cars?. Cheers Neil.
September 7, 2009
Comments: OK I just found out that my 323i does not have a fan clutch but an electric fan, fan shroud. How can I tell if this is the culprit? Sorry for the confusion.
August 31, 2009
Followup from the Pelican Staff: Is it turning on when the car is hot? That's the number one clue. It should be on. If not, it's either the switch, the wiring, or the fan motor itself. Check out the article on electrical troubleshooting for a procedure on how to diagnose something like this. - Wayne at Pelican Parts
Comments: I just ordered the fan clutch. What other electric fan? The fan runs when in idle. I did noticed that in my other car when the AC is on you can hear a fan or something kicking on, but not with the BMW. If that makes sense.
August 31, 2009
Comments: Iam replaceing the thermostat on my 2002 330ci It has a
o ring type seal, do I need to use any other sealant or greese, thank you.
August 29, 2009
Followup from the Pelican Staff: Nope, no additional sealant should be needed. But, if you find it leaks a bit afterward, I usually recommend Curil-T as a good, general-purpose sealant. - Wayne at Pelican Parts
Comments: I have a 2000 E46, 323i with 126,000 miles. It just started to overheat as well as the AC started to get warmer as I'm sitting in line or just let it run idle for a while. As I start to move and gain speed the temp goes down and the AC gets cold again. Should I replace therm, water pump, fan clutch?
August 27, 2009
Followup from the Pelican Staff: Check to see if the electric fans are working first. Then check to see if the fan clutch is working well when idling. I'll bet its one or both of these. - Wayne at Pelican Parts
Comments: Hi. I finally did a coolant change in my '02 330i. When I drained it, I found that the original coolant BMW installed was pink in color. The new BMW coolant I bought is closer to blue. Was it safe to mix these two together?
August 26, 2009
Followup from the Pelican Staff: It should be okay, but if you're really nervous, then change the coolant, drive the car for a few miles, and then change it again. That should get most of it out. - Wayne at Pelican Parts
Comments: '02 530i: Followed instructions above, did the block drain
first, a ton came out of there, moved to the radiator but
the drain plug doesn't come all the way out, it just seems to loosen to open, nothing came out. Is it possible with the ignition turned to position 1 it all cycled out through the block drain ?
August 15, 2009
Followup from the Pelican Staff: There should be some coolant that should still be trapped in the bottom of the radiator. Maybe the screw is stripped? It should come all the way out of the hole. - Wayne at Pelican Parts
Comments: I have a 1987 bmw 325 and my coolant tank has no pressure and i have check my oil its fine my car runs excellent no smoke coming out of the tail pipe and no trouble turning it on at all. I have no idea what's going on i need some help please. Thank you
August 10, 2009
Followup from the Pelican Staff: Hi there. What exactly do you mean by "no pressure?" - Wayne at Pelican Parts
Comments: I have a 1994 318I E36 for the last 3 years. Until now no problems yet. Recently i noticed the engine running hotter. I have bought a cleaning solution, drained the old coolant, replaced it with water and added the cleaning solution. after the cleaning i drained the solution and replace it with fresh coolant and bled the system. For short trips there is no problem. The engine doesn't overhit, but on longer trips the pressure in my cooling system increases so much that it starts to leak at the fill cap. There is no white smoke out of my tail pipe indicating blown head gasket, and there are no leaks present, thus the pressure keeps increasing... Help, what is wrong?
August 5, 2009
Followup from the Pelican Staff: It could be a couple of things. Firstly, I would replace the thermostat and the water pump, as these are often problematic. Then I would bleed the system, and then bleed it again, and then bleed it one more time. BMWs don't have the most robust cooling systems, and having air pockets or bubbles in them can cause overheating issues like these. Also, measure and check your fluid to see if indeed you have a problem with your head gasket. Also check to make sure the overflow tank / hose is working properly and allowing excess coolant to bleed off. Also, if there is a air leak anywhere in the system (sounds like there's one in your radiator cap), that will cause the coolant to depressurize and turn to steam which will hurt the cooling effects and cause the system to possibly overheat. - Wayne at Pelican Parts
Comments: I just bought a 1998 323i convertible E36 with 83,000 miles on it. It is very clean and smooth and I have been driving it for a couple of weeks with no signs of problems about 1,500 miles. The other day I went on a short journey and for the first time put the heater to hot, then I turned it off after a while. When I arrive home I noticed the temperature light became illuminated and the needle was fully across to hot. I left the car overnight rather than take the cap off whilst hot and today found the expansion tank was overful. I drained some water/coolant out and put the radiator cap back and ran the engine. I noticed one seal on the cap needs replacing but I don't think that is resulting in any loss of pressure. Everything seems fine. Any thoughts please?
July 23, 2009
Followup from the Pelican Staff: Hmm, it sounds like there might be an air bubble or something in your cooling system that didn't show up until you turned on the heater. When bleeding the cooling system, you always need to turn on the heater in order to prevent something like this from happening. Perhaps the person who bled the system last didn't do this? I would follow the bleeding instructions, bleed the system, and see if that helps. - Wayne at Pelican Parts
Comments: I just purchased a 2001 325xi. The records from the PO indicate that the last flush was done using generic anti-freeze. I'd like to replace this BMW coolant. Is a drain as described in this article sufficient to remove most of the old coolant? Or should I consider a professional service to ensure that all of the old coolant is removed? Thank you for your informative articles.
July 20, 2009
Followup from the Pelican Staff: Sure, the flush should be good enough. If you're really concerned then do it twice, that should get all of the old coolant out. - Wayne at Pelican Parts
Comments: Following your precise instructions, i removed the radiator and with a little time and minimal effort i completed the job.
Much appreciated the information for a normal old man to do his work and repairs.I live in New Zealand.
July 19, 2009
Comments: E36- Overheated, I let it cool off to operating temp. Then started it up to add coolant with it running. Big air bubbles came out of the radiator filler intermittantly but consistently as it ran, blown head gasket? Blows coolant out filler cap and around water pump when sealed. This is excellent information you have here, thank you very much.
July 6, 2009
Followup from the Pelican Staff: The filler cap and the entire system in general needs to hold pressure in order to keep the cooling system operating correctly. If pressure is allowed to escape, then the coolant will boil. Keeping pressure in the system keeps it a liquid, physics, PV=NRT. So, if you fix any coolant leaks that you have in your system, you should solve your overheating problems. - Wayne at Pelican Parts
Comments: I just swapped out the radiator on my e36 and after refilling all of the fluids it still wants to overheat. I refilled the coolants according to this guide. Any suggestions?
July 6, 2009
Followup from the Pelican Staff: It could be one of a few things. I would replace the theromstat (recommended when you replace the radiator), as it may be stuck. I would also think about replacing the water pump - the impellers might be broken. Finally, run the car for a while cold, without the bleed screw attached, and let the system bleed all bubbles out of the top. Hope this helps. - Wayne at Pelican Parts
Comments: place a filter underneath the engine block coolant drain plug and you can direct the flow into a receptacle, minimizing mess. Make sure the hole is big enough in the bottom of the filter so the plug screw doesn't stop it up when it comes out. Also, loosen from the top from over the wheel-well. It's hard to torque the screw loose, but you minimize messing on yourself.
July 3, 2009
Followup from the Pelican Staff: Good suggestions here - this is a messy process. - Wayne at Pelican Parts
Comments: Is draining the coolant enough or should I also flush the cooling system? I'm also replacing the water pump, t-stat housing, t-stat, upper and lower radiator hoses, replacing the expansion tank cap and both both belts. This is being done on a M52.
June 19, 2009
Followup from the Pelican Staff: Draining is typically enough unless there's something serious wrong with the existing coolant (like oil and water have mixed from a head gasket failure). - Wayne at Pelican Parts
Comments: I'm assuming that these instructions are identical for the 4 cylinder M44 engine?
Also, does the climate control need to be running during the entire process or is there a point when it can be switched off?
May 21, 2009
Followup from the Pelican Staff: Yes, very similar for the 4-cylinders. Some of the plugs might be in slightly different locations. As for the heater, you need to run the heater in order to remove the coolant from the heater core. I like to keep the system on during any work like this. - Wayne at Pelican Parts
Comments: On the M52 engine U.S., does the sensor on the exhaust manifold need to be removed before you can remove the coolant drain plug on the engine block?
April 29, 2009
Followup from the Pelican Staff: If you're referring to the oxygen sensor (O2 sensor), then no, I think there's ample room in there to get to the plug to empty the coolant. - Wayne at Pelican Parts