Parts Catalog Accessories Catalog Tech Info Tech Forums
 
Follow Pelican Parts on Facebook Follow Pelican Parts on Twitter Follow Pelican Parts on Instagram Follow Pelican Parts on YouTube Follow Pelican Parts on Pinterest Follow Pelican Parts on Tumblr
  Search our site:    
View Recent Cars  |   Cart  | Project List | Order Status | Help    
 
Get FREE Ground Shipping with the purchase of $75 in qualifying parts!
 


Pelican Technical Article:

BMW Thermostat
Replacement

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. 

[click to enlarge]

Figure
Figure 1

Figure
Figure 2

Figure
Figure 3

Figure
Figure 4

Figure
Figure 5

Figure
Figure 6

Figure
Figure 7

Figure
Figure 8

Figure
Figure 9

Figure
Figure 10

Figure
Figure 11

Need to buy parts for this project? Click here to order!

     BMW cooling systems have been known for being troublesome for quite some time.  One of the principle areas of failure are the thermostat and water pump.  Overheating problems are common on these cars, and if your engine overheats, you may find yourself having to replace your head gasket, which is not cheap.

     Begin the process by gaining access to your thermostat.  This requires the removal of the fan and belts, as well as the removal of all coolant from the system.  See the following technical articles for instructions on how to get to this point:

     With all of your equipment removed, the front of your engine should resemble Figure 1, and you should see the black plastic thermostat housing.  Remove screws that attach the housing to the cylinder head.  Pull off the thermostat housing (Figure 2).  It may require just a little bit of force to remove if it's caked on there.  The thermostat can be pulled out of the head now (Figure 3 - shows the head removed from the car).  Figure 4 shows the backside of the thermostat.

     Install a new thermostat into the cylinder head using a new o-ring to seal it to the head (Figure 5).  The thermostat should fit snuggle into it's bore in the cylinder head.  Make sure that the o-ring is seated properly (Figure 6), and that the small vent hole or arrow faces up.  Use a new seal on the thermostat housing (Figure 7).  If your head has been damaged by corrosion and electrolysis (Figure 8), then you may want to add some black silicone sealant to the thermostat housing when you install it (Figure 9).  Figure 10 shows the thermostat housing remounted with an appropriate amount of squeeze-out from the black silicone.  Figure 11 shows the thermostat housing reattached to the head, and the flywheel sensor cable correctly routed around the housing.

     Well, there you have it - it's really not too difficult at all.  If you would like to see more technical articles like this one, please continue to support Pelican Parts with all your parts needs.  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.  Your continued support directly affects the expansion and existence of this site and technical articles like this one.  As always, if you have any questions or comments about this helpful article, please drop us a line.

Comments and Suggestions:
Rudebwoy Comments: Hi I just replaced waterpump, thermostat, ac compressor and serpentine belt on my 2007 525i bmw with n52 engine, did a code read and getting this code, p0597 thermostat heater circuit/open nothing on the idrive, what could be the cause?
November 25, 2014
Bronda Comments: Hi, I really need some help..I am a woman and i know nothing about cars...I have a BMW 330i 04'. I have cold air coming out when the heater is on and after it runs a while the hand goes to the hot side. When i put on breaks or when i park the car and cut if off steam comes from the front. The fan in the front of the radiator also doesnt move when it is parked but on..Please Help Me Thanks
November 24, 2014
  Followup from the Pelican Staff: Sounds like a coolant leak. I would pressure test the cooling system. If the system will not hold pressure and there are no external leaks the head gasket may be faulty. I bet you find the radiator, reservoir or a hose leaking.- Nick at Pelican Parts  
Doni645 Comments: What if it only overheats while in highway or driving but not when it is still.
I changed the waterpump, radiator, fan clutch, bleed and once tried it with no thermostat and it still overheated only while driving a couple miles like in the highway, but won't overheat when it is running still. Please anybody know?? Thx
November 19, 2014
  Followup from the Pelican Staff: Could be a restriction or a faulty head gasket. - Nick at Pelican Parts  
Spadehead Comments: Hi,

I have a 2002 525d and the temp gauge never really gets to midday. Hovers mostly at around a third. I drained coolant and replaced, have also replaced egr stat but still the same. Have checked on computer and registers between 60 and 82 degrees but fluctuates and never really stays constant. Urban driving heats up more and it usually drops on motorway driving. Have you any ideas what I should check next?

Thanks .
November 16, 2014
  Followup from the Pelican Staff: We don't have that engine here, so I am not familiar with it. Did you replace the coolant thermostat? If so, is the cooling fan on all the time or mechanical fan noisy? - Nick at Pelican Parts  
Pete Comments: Greetings,

Following problem with E61 525i N52b25. Heater drops engine temp from 95C to 75C in a few seconds, when adjusted to warm outside temp ~ 0 C I have replaced main thermostat twice, but no changes. Heater just drops engine temperature. If heater is switched off engine heats up. Is this anymore a thermostat problem???
November 7, 2014
  Followup from the Pelican Staff: I would think the thermostat is the issue. Only other thing that pops into mind is if the cooling fan is on all the time. - Nick at Pelican Parts  
JP Comments: If my engine is overheating and has enough coolant, how would I determine whether it is the thermostat or the water pump?
Thank you so much
November 3, 2014
  Followup from the Pelican Staff: If you have one cold and one hot radiator hose, the thermostat may be faulty. If you have hot hoses, and no flow the water pump is faulty. You didn't mention what vehicle you have, so I can't be more specific. - Nick at Pelican Parts  
Kingkreame Comments: I have a 2002 525i an the temp gauge is swaying tward the red it doesn't go into the red but it sways back an forth. I think its my fan cluch cause its making noise do u know if this could be correct
October 16, 2014
  Followup from the Pelican Staff: Is the coolant level OK? If the fan clutch stiff when cold, then moves when warm? - Nick at Pelican Parts  
Pink Comments: My 1992 e36 Bmw 316i is heating. I replaced te head joints butn it would still warming. But before replacing the joints, my mechanic removed the thermostat claiming its malfuctioning.Could removig thetermstat cause the engine heating?
September 8, 2014
  Followup from the Pelican Staff: I would pressure test the cooling system. If the system will not hold pressure and there are no external leaks the head gasket may be faulty. - Nick at Pelican Parts  
mloro Comments: Hi i have 118i BMW 2007 I have just replaced the cracked radiator and put on new upper and lower hoses i also have done pressure tests which revealed a blown head gasket and suddenly it got oil and water mixed in the radiator ..does all all this mean new head gasket and will my car run as efficient as it was after head gasket replacement..plus the fan does not kick-in after warming..do i replace the bottom fan switch or is this a result of a blown-up head gasket?
September 4, 2014
  Followup from the Pelican Staff: If you found a bad head gasket, then yes repairing it will help your engine. However, have the head tested when it is removed, to be sure it isn't cracked or warped. - Nick at Pelican Parts  
Mikemo Comments: I have a 2001 330i. I'm having problems with it overheating, it all started right after I did an oil change.I took it for a spin, I pulled into my driveway and notice fluid coming out the bottom of my car. I look under a notice hoes that was disconnected from the antifreeze housing area. I connected it back and put a clamp on it. I started the car after putting antifreeze in it and it ran for about 5 minutes before it started over heating. I took the thermostat off to see if it would fix the problem and tell if it was that or the water pump. I started the car again after removing the thermostat and it ran this time for about 10 minutes before over heating. Im assuming its the water pump but not to sure. Help please.
August 11, 2014
  Followup from the Pelican Staff: I would pressure test the cooling system. If the system will not hold pressure and there are no external leaks the head gasket may be faulty. if it holds pressure, check that the bleed hole in the reservoir has a stream of coolant coming out. if it does not, the water pump may be faulty. - Nick at Pelican Parts  
94' 325i Comments: Here is the picture of lack of flushness
July 29, 2014
  Followup from the Pelican Staff: Thanks, got it. - Nick at Pelican Parts  
94' 325i Comments: I recently bought a 94' 325i from a private party and it started overheating. I took the housing off and the thermostat is missing. I bought a new thermostat and housing to replace from O' reileys and it is too big. Same thing with autozone. As far as the bmw dealership "knows" the thermastat is universal from 92-99ish. I was wondering if you guys could visually identify the engine or if I have to find the block serial.
July 29, 2014
  Followup from the Pelican Staff: Looks like the old one is still in place. From the photo you shared. - Nick at Pelican Parts  
spudgun Comments: I have a 2001 320ci m54 engine, just changed the thermostat due to a fault code, now the car won't rev up and will just stall after about 10 seconds at idle.
July 21, 2014
  Followup from the Pelican Staff: Check if the intake air boots are connected correctly. If so, might be a coincidence. I would start by checking the DME for fault codes. If the system is not working properly, a fault code will be set. This will be your best bet when diagnosing.
- Nick at Pelican Parts
 
despaired Hans Comments: Hi: I have a 318ti 97 BMW I got a water leak in back of engine coms out as fast as I poor it in, cant locate where it is coming from . what would I have to remove to get to it?? Please HELP Many Thanks despaired
June 22, 2014
  Followup from the Pelican Staff: Could be the plastic coolant pipe that runs behing the engine. You should be able to replace it without removing too much. Use a mirror to confirm this is the issue. The pipe runs along the back of the cylinder head, near the fire wall. - Nick at Pelican Parts  
LUke Comments: Hi, I have a 1982 bmw 320i. My AC only works on high, which is the classic sign that my blower motor resistor is blown. I bought a new resistor but I don't know where the find the old one. Where exactly on the 320i is the AC blower resistor located? I can't find it anywhere.
June 8, 2014
  Followup from the Pelican Staff: It's located on the blower motor, which is mounted behind the wiper cowl. Accessed from under the hood. - Nick at Pelican Parts  
Edd Comments: Replaced the radiator on my 2005 325ci yesterday. Filled with coolant, drove fine. went about 5 miles when it overheated. Any thoughts? Are there two thermostats?
May 14, 2014
  Followup from the Pelican Staff: Was it overheating before the repair? If not, it is likely trapped air. I would try filling and bleeding the system again. - Nick at Pelican Parts  
WestSideWolf Comments: Another follow up, I installed the new thermostat housing, the new hoses, the new gaskets however now I notice my cars engine is hot enough to make eggs on it as are the hoses that go into the rad and engine what could cause this?

Air in the system or something of the sort? I don't believe it could be the thermostat its brand new as well unless it got installed backwards which I doubt it as I used your guide here anyways advise would be welcome, by the way its a 1988 bmw 325i convertible.
May 12, 2014
  Followup from the Pelican Staff: I would start by filling and bleeding the system again.
I would pressure test the cooling system. If the system will not hold pressure and there are no external leaks the head gasket may be faulty.
- Nick at Pelican Parts
 
rob Comments: hello, i have a bmw 318 coupe E46 on a 2005 plate, i have recently had bit of trouble with my temp gauge / cooling system .
basically while driving the car cold the temp gauge goes up but just before it hits the 12 ' o'clock point it will drop down to quarter way down on scale then build back up to the 12 o'clock point gain. this will happen 2/3 times then after about 15 min of driving its fine.
i went to the "hidden menu" and went for a drive the highest temp was 103 for about 1min and then it stayed at about 93'celsius. when the problem happened the temp dropped down to roughly 50/60'c and built back up to 93'c . it has once flew up to the red zone for no longer then 2seconds the red light never came on tho which i hope to think is a good thing : .
May 3, 2014
  Followup from the Pelican Staff: Sounds like a faulty thermostat. I would check coolant level, then check operation of the thermostat. - Nick at Pelican Parts  
west_side_wolf Comments: Follow up on my previous post, figured out what it was I stripped a thread of the blue sensor that goes into the thermostat housing.
Ended up buying a new thermostat housing and ill replace today any advice?
May 3, 2014
  Followup from the Pelican Staff: Check that the sealing surface isn't pitted when replacing the thermostat. - Nick at Pelican Parts  
Hugh Comments: FYI only - My previously reported "coolant level" error messages were due to a faulty coolant level sensor located at the bottom of the radiator expansion tank that would sense "no water" unless the expansion tank was totally full.
Thanks again, Hugh
April 25, 2014
  Followup from the Pelican Staff: Makes sense. Thanks for the follow up. We appreciate it.
- Nick at Pelican Parts
 
WestSideWolf Comments: Hello, I have a 1988 BMW 325i Convertible
I noticed when I turned on the car its temp gauge would jump from cold to hot with out even being on for all of five mins.

So what I did was I replaced the thermostat, however it still occurs so I ordered new coolant sensors and etc

But Im still unsure because it idles rough like a smokers cough before it never had any issues. So I'm wondering what it could be.Thanks.
April 23, 2014
  Followup from the Pelican Staff: Sounds like you have an engine misfire. I would guess the coolant gauge issue is a separate issue.

I would start by checking the DME for fault codes. If the system is not working properly, a fault code will be set. This will be your best bet when diagnosing.
- Nick at Pelican Parts
 
ggh Comments: I have a 523i 97, i had lack of water, i chnaged the radiator and after i changed the engine 3 weeks ago, but i still have a lack of water, canyou help m plz
April 23, 2014
  Followup from the Pelican Staff: I don't understand what you mean by lack of water. Can you be more descriptive?- Nick at Pelican Parts  
dodge Comments: I have a bmw x5 2005, need to know how to remove a double coolant temp sensor from the cylinder head in back of engine. Please help
April 22, 2014
  Followup from the Pelican Staff: We do not have a tech article for that procedure. If we get the chance to perform the repair, we will be sure to document the procedure. For now, you can grab a repair manual. - Nick at Pelican Parts  
Socalsunshine Comments: If I change the water pump on my car do I need to also change the thermostat? The diagnostic code came back water pump needing repaired but nothing about the thermostat. It is a 2006 BMW 330i.
April 21, 2014
  Followup from the Pelican Staff: You might as well, as they are installed close together. I always leave it up to the person paying the bill, as it can add some cost. If you can, do both. - Nick at Pelican Parts  
Hugh Comments: I should have added that the specific fault is "cooling level". Also, I have immersed the temp sensor in water coming to a boil. The normal speed switch closed as the water was nearing boiling, the high speed sw. after the water was boiling for 2 minutes. If I top it off w/ a pint the msgs go away briefly. A blockage? Thanks again, Hugh
April 21, 2014
  Followup from the Pelican Staff: If you add coolant and the message goes away, the system must be low. Have you pressure tested it for leaks? - Nick at Pelican Parts  
Hugh Comments: I have a 1993 325is. It runs fine and the temp gage climbs to the mid point and then stays there. However when I stop I get the coolant temp sensor error msg. Also I have never heard my electric fan run, neither normal nor high speed but both speeds work when I jumper the fan ctrl temp sw terminals. Many Thanks Hugh
April 18, 2014
  Followup from the Pelican Staff: You could have a faulty coolant temp sensor. I would check for fault codes using a BMW scan tool. If you have a fault code for the sensor, test it and replace if needed. - Nick at Pelican Parts  
Ange Comments: My 97 328 stat housing is cracked, so i basically chiseled off the rest. It was a tight fit for taking the fan blades out. Is it possible to get the housing back on without having to take the fan clutch off? I tried without the special tool but just couldn't grip the w/p pulley to hold still.
April 1, 2014
  Followup from the Pelican Staff: I'd say your best bet is to remove the fan. it will be very tight, if at all possible to get the new one in without doing so. - Nick at Pelican Parts  
e36_frisco Comments: Hi I have a 95 318i 4 cyl..it runs great but I recently had a radiator leak and replaced it..but now when I leave the car running on idle it starts slowly overheating after about 30-45 mins of sitting..once I start driving it goes down to normal temperature..I have been reading about having a fan behind the radiator and my car doesnt have it..can that b the problem? I only have the fan thats connected to the belts and the water oump..pls help
March 28, 2014
  Followup from the Pelican Staff: You viscous fan may be faulty. Or the lack of the electric cooling fan. I would check the viscous fan operation. Also, call our parts specialists with your VIN. They can help you figure out if you should h ave an electronic cooling fan. - Nick at Pelican Parts  
kris Comments: Hi I have a 1989 e30 318i that is being a bit sketchy, sometimes when I'm at Traffic lights or after starting up it will struggle to keep its revs and after a few times bobbing up and down it cuts out, what is this? Also some times happens if I let it coast in neutral to come to a stop, one day it happened loads and the next it would be fine. Its the m40 engine and I cleaned out the idle control valve when my mechanic suggested it, sounded nice for like 1 second then went back to a diesel sound. HELP
February 24, 2014
  Followup from the Pelican Staff: COuld be a vacuum leak or a faulty idle control valve. I would check the system using a BMW scan tool. - Nick at Pelican Parts  
mook Comments: I have a 1997 528i my car recently overheated and all oil and coolant leaked out tried to pour water in but it kept rejecting it let it cool off drove a mile and it overheated again what's the problem??
February 20, 2014
  Followup from the Pelican Staff: Sounds like a faulty head gasket. - Nick at Pelican Parts  
grandad Comments: 1999 bmw e46 series e temp gauge reads red hot before eng start advise please
February 17, 2014
  Followup from the Pelican Staff: This can be from a lack of data from the DME over the bus. I would check the vehicle for fault codes using a BMW scan tool. - Nick at Pelican Parts  
frisko Comments: I have a 323i that I have recently changed the thermostat and overflow tank on. the engine oil warning light now comes on. the engine oil level is at the appropriate level. Could the cause of this be the oil thermostat? also we live in a cold climate and use the heater frequently at times the heater will begin to blow cold air even similar to engaging the air conditioner.
February 15, 2014
  Followup from the Pelican Staff: I would suspect a drop in oil pressure or a faulty sending unit. Install an oil pressure gauge and check engine oil pressure. - Nick at Pelican Parts  
Conner71 Comments: I have a 93 BMW 325i and just replaced the thermostat. Everything fine until 2 days later when there was quite a leak after starting. It doesn't appear to leaking around the thermostat housing but more like a possible water pump leak. Would this be something that would commonly go hand in hand with the thermostat replacement? If so, is there a way to know for sure that that's the problem? Thanks, Mike
February 14, 2014
  Followup from the Pelican Staff: Could be a coincidence. I would pressure test the cooling system and pinpoint the leak. - Nick at Pelican Parts  
pmh22 Comments: Have a 97 318i, when driving the thermostat housing broke away from the engine and coolant went everywhere through engine bay. Replaced the part, cleaned engine bay and refilled & bled coolant. Ran ok for a while but then started overheating periodically.
One day was driving on the freeway and car lost all power without any overheating issue or temp alerts, and would not restart. Towed home on a trailer and since have replaced fuel pump and fuel filter, managed to get it started, it's idling very rough, blows white smoke.
No codes coming up.
Someone suggested water pump or head gasket?
February 14, 2014
  Followup from the Pelican Staff: I can't help without knowing what is missing from the system when you are trying to start it. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and pressure fuel, volume and quality. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.
- Nick at Pelican Parts
 
Jeremy Comments: I have a 1988 E30 BMW 316i and it keeps overheating. I have replaced the water pump and the themostat. The car also will not blow out any hot air. There is no coolant that is leaking out from anywhere. Any ideas on why it could be overheating?
February 10, 2014
  Followup from the Pelican Staff: Could be air trapped in the system, a restriction or a faulty head gasket. - Nick at Pelican Parts  
scavey Comments: i have 2002 bmw 320 petrol the car runs good.but no overheating.but no sometime the coolant goes low,like l have to check every 3days but no leakage but have realise is the seal cap of the coolant when driving the water or vapour comes out,does that mean the cap is not good and need to change.i put leakage stopper in the coolant to stop any leakage.but now am experiencing some milky thing in coolant but the water is cleear and the oil is clear no water in the engine oil.but the engine oil cap look like milky.like vapour water on the cap.
February 9, 2014
  Followup from the Pelican Staff: The milky substance could be the leak stopper. If there are no external coolant leaks and the system will not hold pressure, you may have a faulty head gasket.- Nick at Pelican Parts  
scavey Comments: hi l have bmw 02 model before l start the engine.when l turn the key the thermostat gauge goes to red even the engine is not on.but when l start it start and goes off.and when l start the engine stay on and the gauge goes back to normal.no overhearting the car runs good.
February 9, 2014
  Followup from the Pelican Staff: The needle may sweep for a self-test. if there are no other issues, I would not worry about it. - Nick at Pelican Parts  
Randi Comments: Hi I have a 2002 bmw x5......my thermostat won't come on but my heat still blowing but when I turn my truck off but the air still blowing. Can you please tell what that can be? This truck is giving me the blues right now.
February 6, 2014
  Followup from the Pelican Staff: If the blower motor is stuck ON, the final stage unit may be faulty. - Nick at Pelican Parts  
Ted Comments: Hi,
I have an e36 318i convertible, I've got a rather strange issue, the engine will not heat up past about 10 oclock, occasionaly it reaches normal temp if I cruise at 90-95 for a period of time. However what I find strange is that the heating will only blow hot! but on the few occasions I have reached the 12 oclock mark it works properly and then when it cools again it blows hot again. I've had a new waterpump fitted about 3 months ago. So might this be the thermostat, I can only imagine it's stuck in the open position, but why would this affect the heating like this?
February 5, 2014
  Followup from the Pelican Staff: I would check to see if the thermostat is operating correctly. Check if the vehicle warms up quickly when started cold. If not, the thermostat may be faulty. - Nick at Pelican Parts  
Cynthia Comments: And now the heater isn't blowing any hot air again!
February 3, 2014
  Followup from the Pelican Staff: OK, got it. - Nick at Pelican Parts  
Cynthia Comments:

Thank-you for answering. The ambient stopped first and then a few hours later, I noticed the temp gauge would not get out of the blue area.
February 3, 2014
  Followup from the Pelican Staff: I would start by checking for fault codes. If the sensors are shorted or open, there will be codes. You can also performa system test of the cluster. - Nick at Pelican Parts  
Cynthia Comments: Hi. I have a 1996 BMW 328i. My car has been working great but yesterday my ambient temperature sensor stopped working stays at -37C and now my temperature gauge doesn't get out of the blue. I have heat blowing through the heat vents. Are the two somehow connected? If not, what could be the problem?
January 27, 2014
  Followup from the Pelican Staff: The two are separate sensors. I would check if the ambient sensor is connected, it sounds like it is not. The sensor remaining cold for the engine, tell me that circuit is open as well. Did they both fail at the same time? - Nick at Pelican Parts  
Dav001 Comments: I have had my E46 318 I for 7 months now. Temperature goes up to 1 o'clock before the red zone if I drive on uphill road , when A/C on and if I stuck in traffic or , when I stop in an up hill road . Also, when I put a bit of pressure on the engine by fasting and keep the RPM high for a bit.
However, the temperature will go back to 12 o'clock after few minutes.Is it a fan switch ?
January 20, 2014
  Followup from the Pelican Staff: This sounds more like the beginning of a head gasket issue. I would check operation of the cooling fan at idle, confirm it works in all speeds. Then check coolant level and pressure test the cooling system. If it does not hold pressure yet has no external leaks, I would suspect the head gasket. - Nick at Pelican Parts  
zac001 Comments: I have E46 318I BMW 1998. I have a temperature rising problem but it is a very weird. Sometimes I drive for hours and no issue but sometimes driving short distance temperature goes up very quickly before the red zone stay there for 1 minute then temperature goes back down , It happens in up hill or AC on in traffic. Last night temperature went up to red zone stayed for 3 minutes before come down .No liking water for sure, fan works but not loud fan very soft. Any ideas?
January 19, 2014
  Followup from the Pelican Staff: This could be a faulty thermostat or coolant level problem. Check coolant level, be sure it is properly bled, then check operation of the thermostat. - Nick at Pelican Parts  
Eric m Comments: Hey .. I had a faulty radiator. And I got it changed and now I don't have steam coming out of my car but my temperature hand stays in the middle until I drive it .. Could it be that the tstat needs to be changed or the resivor tank ..? Or both because I checked it this morning and saw that my coolant leaked out of the resivor tank on to the ground. I have a 2002 325 ci coupe.?
January 19, 2014
  Followup from the Pelican Staff: If the engine is overheating air could be trapped in the system. Or the thermostat or other components could be faulty. I would bleed system, then check for proper coolant flow (raise idle, bleed hole in reservoir should have steady stream of coolant), then check operation of thermostat. - Nick at Pelican Parts  
slick Comments: i have a 1996 318i temp barely gets out of the blue, heater dosent heat like it should. temp drops lower when driving is this a thermostat issue?
January 17, 2014
  Followup from the Pelican Staff: Sounds like a stuck open thermostat. - Nick at Pelican Parts  
Danguy Comments: Hi I have a 2002 bmw x5 44i when I go to start the car it go strait to the red an go's off but the car is cold I know it not over heating any idea what this might be HELP....
January 9, 2014
  Followup from the Pelican Staff: It could be a faulty coolant temp sensor. If the circuit is open, it will read full hot. - Nick at Pelican Parts  
beemerlover Comments: Hi, my 2004 320i temperature gauge will stay at 12 O'clock while its idling but as soon as I start driving short distance it will go into the red, after I turn it off a wait it goes back to 12 and then goes down then back to 12. No heat blows unless I am driving, any suggestions?
January 6, 2014
  Followup from the Pelican Staff: This sounds like a bad head gasket. Start by checking that the cooling system is full and air-free. Then pressure test the cooling system. If the system doesn't hold pressure and does not have any external leaks, the head gasket may be faulty. - Nick at Pelican Parts  
nickelmrl Comments: I recently replaced the thermostat in my 330i - the old one was leaking - but the system was working - no overheating just the leak. After the replacement I bled the system, but first time the car ran it wouldn't warm up. Now there appears to be a leak in the new Thermostat different though - lots of steam/coolant under pressure coming from under where the electrical connector connects to the thermostat housing. The car also overheats now despite having coolant in the system and it being bled. The lower radiator hose seems cooler than the upper. Is it possible the new thermostat is faulty?
December 30, 2013
  Followup from the Pelican Staff: Yes, possible. I would remove it and check that the sealing surface on the head ins't pitted. If not, trade that thermostat for another new one. - Nick at Pelican Parts  
Blk323 Comments: I think my Tstat is stuck open bc car temp stays at the 2nd line not reaching 12oclock. Ho do I determine if this is the case, and what other components if any need replacing? Btw my car is a '98 323is with 87k miles and. I cooling upgrades/rplcmts by previous 2 owners to my knowledge.
December 15, 2013
  Followup from the Pelican Staff: With the engine cold, start it and monitor the hose temps near the thermostat. they should not warm up slowly with the engine. They should remain cooler until the thermostat opens. - Nick at Pelican Parts  
Blk323 Comments: Hi, I have no mechanical experience but would like to attempt to DIY my cooling system... Is it doable? What are all the tools/materials I'd need? Thank you!
December 15, 2013
  Followup from the Pelican Staff: If you are mechanically inclined, go for it. Give our parts specialists a call at 1-888-280-7799 and they can help figure out which part or repair kit you need.
- Nick at Pelican Parts
 
hassib Comments: hii;
i have e46 325ci convertible 2002,i have changed the thermostat,the expansion tank,and the cup and i have bleeded my cooling system 3 or 4 time but i have a pressure inside my expansion tank after one night stay when my car is cold,can you please help me to resolve issue?kindly note that there is no leak and no overheating,and no water inside the oil;
December 9, 2013
  Followup from the Pelican Staff: It is possible for a head gasket to be faulty in such a way that combustion pressure leaks into the cooling system. This can be tested (very carefully) by using an emissions tester on the radiator or expansion tank. - Nick at Pelican Parts  
don Comments: I have a 2001 BMW X5 and the thermostat is all one piece with the housing. No problem. But my question is how do I safely disconnect the hoses from the housing? It does not use clamps but has what looks like it will be a tapered fitting probably with a rubber ring.
How do I release the hoses? I suspect prying at some point on the fitting will release the lock. Can you shed some light on this?
November 29, 2013
  Followup from the Pelican Staff: Pull off the spring clip right at the hose junction to remove. - Nick at Pelican Parts  
Cat Comments: I have a X5 2002 and temperature reading was either in the blue 99% or in the red 1% of the time. I had the thermostat replaced but the mechanic did not follow the dirctions that this site gave, he replaced it without removing all the coolant from the system and instead just filled it back up after thermostat was replaced. I haven't had any problems YET with the temperature going into the red but the coolant ony heats up when I am idling, when I drive the car it cools down and causes the heat not to work efficiently does not blow really warm air regardless of what temperature you have the heat on. The BMW dealer suggested that the system needs to be bled to make sure there is not an air pocket in the system. Is there anyway to test this without taking it to the BMW dealer?
November 25, 2013
  Followup from the Pelican Staff: Air in the system will prevent heat, but not the engine from warming up. I would double for a properly bled cooling system. Then check that the thermostat is working properly. If the vehicle cools off while driving, it may be defective. - Nick at Pelican Parts  
al Comments: Hi... I have BMW 1997 318i and I overheating I change the water pump and I change the thermostat and stale overheating but the fan stay in low speed can you help me with this plaes
November 16, 2013
  Followup from the Pelican Staff: I would check the fan and the fan switch, if the fan will not work correctly, that could be your problem.
- Nick at Pelican Parts
 
BarbsMeanWheels Comments: Hi,
I have a 97 328is that I have owned now for 3 years. Bought it with the rad, water pump and stat replaced just months by the previous owner. Purchased it in warm weather and runs no more than 1/2 way on the gauge.. sounds normal right? I live in Canada, and I store the BMW's when the snow starts, but this time of year, when the running on the "interstate" the gauge will no get off the blue portion of the gauge. Vents blow mostly cold now after 3 years, but was kind of warmer in prior years. No coolant usage, no leaks....possibly a low temp stat? replace the stat ? or just move to California! thanks.
Our '93 325i does run in the middle on the gauge all the time...I think, don't drive it much.
November 11, 2013
  Followup from the Pelican Staff: I would start with a new thermostat. Sounds like you are on the right track. - Nick at Pelican Parts  
Josh Comments: My 1986 325e does not overheat I think, the temp gauge is broken, so I think the thermostat has failed open - when starting cold, idle is very rough and too low, around 400-500 rpm, sometimes dipping to 200 but not stalling; and slowly goes up to 600 and quite smooth when the car is warm. Could this be the cooling system working too well/thermostat stuck open, or an issue with the oxygen sensor missing, soon to be replaced or something else?
November 10, 2013
  Followup from the Pelican Staff: If the o2 sensor is missing the engine will not run correctly. I would start there. - Nick at Pelican Parts  
big-daddy Comments: i have, rather my son has a 98 328is with 140k, I just work on it!! changed thermostat, flushed coolant and refilled. bled to your specs with all air out. over heated first time after running a while, re-bled for air bubble, same effect. took out thermostat no problems now. what is the trick with the new installation of thermostat. no arrow on the new t-stat and no bleed hole either. what is the proper install position?
November 4, 2013
  Followup from the Pelican Staff: I think you had the Tstat in correctly the first time, I would start looking to the water pump for a flow problem, or maybe do a compression and leak down test to check for a blown head gasket. - Nick at Pelican Parts  
flustered Comments: I have 03 bmw530i. Recently I have noticed smoke coming from under the hood and the smell of coolant coming from her too. The tempture gauge will be normal in the middle then say I am over heating, and then a min later say I am normal temp again, in the meantime my heat inside my car is going from coldno heat to warmworking fine. I put coolant in her which doesnt seem to do anything because ten min into driving my check coolant light comes on I have had the thermostat replaced about two months ago, and in this time she seems to be running normal, could this be the radiator?
October 24, 2013
  Followup from the Pelican Staff: You are going to have to pressure test the cooling system to find and fix the leak.
- Nick at Pelican Parts
 
Bagger Comments: Fighting infamous 318iS overheating problem. Radiator, water pump, clutch fan and t-stat has been changed. Drove the car all summer without a t-stat. No problem. It's getting cooler now, installed a new one and it's back to running warm. I believe the system is adequately bleed. I'm getting good heat. As a matter of fact running with heat on is keeping the gauge from going all the way to the right. Am I overlooking anything?
October 18, 2013
  Followup from the Pelican Staff: I would perform a pressure test, leak down test, and a compression test to make sure the head gasket is ok, I would also check the air flow across the rad to make sure it is not plugged.
- Nick at Pelican Parts
 
leo Comments: i have a 92 525i ,i did everything, but my thermostat is wedged in there i cant pull it out! is there a simple way or at least a way to get it out?
October 16, 2013
  Followup from the Pelican Staff: If the housing has been removed and the thermostat is stuck, you will have to pull it out. Try grabbing the center support with pliers and pulling it out. You may have to wiggle it side to side to free it. Work carefully, you don't want to damage the engine. - Nick at Pelican Parts  
Jake Comments: Hi there, i have a 97 e36 328i i got it from a friend who said it had trouble overheating on a winter morning and has sat for atleast a year, when i got my hands on it i noticed that the thermostat housing had cracked so i got to work and replaced it with a new metal housing and thermostat. I started it up and the heaters stay cold up until the car reaches the red in temp, i tried pouring water into the expansion tank and opening the bleed screw, but no coolant seems to reach the bottom hose and when you squeeze it it feels of nothing is in the or even coolant? Should i try bleed the system via a few posts from forums ie. bleeding with the ignition on and engine off? I also get a hissing noise from somewhere around the from and the car takes coolant but doesnt seem to leak anywhere or is this also down to not bleeding the system properly?
Many thanks Jake!
October 12, 2013
  Followup from the Pelican Staff: I would pressure test the cooling system. If the system does not hold pressure and there are no external leaks, you may have a faulty head gasket.
- Nick at Pelican Parts
 
dj groove Comments: hey ive got a 1992 bmw 325i i did a radiator flush then new coolent in and when i turned car on to bleed air out after bout 5 to 8 mins would start bubbling and boiling and spiting water our of the expanison tank and the bleeding hole would dr5y up and spray steam after had bubbled a little bit why and how do i fix this
October 2, 2013
  Followup from the Pelican Staff: Let the engine cool off and fill the system when it is cold. Then start the engine and open the bleeder. When coolant starts to come out close the bleeder and let it run. Does the car overheat and bubble in the expansion tank then? - Kerry at Pelican Parts  
henri Comments: Hi! I have a 1988 320i Baur since a couple of months.
drives lovely but I have two problems:

1 when I drop a gear or just let it brake on the engine, the gears make a grinding noise.
2 I am consuming a lot of cooling water. I have to fill up the reservoir every 100miles which looks like too much... I checked for leaks, checked the temperature and the heating and those all work fine....

can somebody please help me?
October 1, 2013
  Followup from the Pelican Staff: Sounds to me like you have bad head gaskets or a cracked block or head. For the grinding noise while decelerating try putting it in neutral, does it still make the same noise? - Kerry at Pelican Parts  
Rollan Comments: I just had my thermostat housing replaced on my 325i. When I got back home and turned the car off, it made a gurgling fluid sound. Did the mechanic make a mistake fixing my car?
September 30, 2013
  Followup from the Pelican Staff: They probably did not completely bleed the system of air. You may want to take it back to him or bleed the cooling system yourself. Check out our tech article on bleeding the cooling system and see if it is something you may want to try - Kerry at Pelican Parts  
Steviep Comments: I have a 1992 325i E46 2.5DOHC i did the thermostat and water pump now the lower rad hose is not getting any water what do i do did i end up with the joy or redoing the thermostat again because i ended up with a faulty one.
September 18, 2013
  Followup from the Pelican Staff: Sounds like you have air trapped in the cooling system, open the bleeder screw in the upper hose until coolant comes out, top off the coolant tank and check that there is flow at the tank while the engine is running. If there is not coolant flow check the water pump.
- Nick at Pelican Parts
 
Wavecruzer79 Comments: Helping a friend diagnose a 96 318ti over heating issue. The radiator was just replaced. The electric fan won't cut on but I can jump the terminals at the temp sensor side of the radiator the high speed works, low speed won't. This test is in the manual. Facing the motor the upper hose gets hot...really hot. The lower radiator hose stays cool. Thinking thermostat not opening or air trapped from radiator repair so guy did in the driveway. The heat will not work either. I'm thinking empty the fluid and try to fill again while bleeder plug is out to remove trapped air, and or replacing thermostat. Any ideas?

Thanks
September 18, 2013
  Followup from the Pelican Staff: I would start by replacing the thermostat, and then filling the cooling system and making sure all of the air is out. Check to make sure you have coolant flow at the coolant tank when the engine is running, if not the water pump could be faulty.
- Nick at Pelican Parts
 
Kwest Comments: Hi I really need help. My water bottle apparently is damaged. My heat was always on half but I used to top-up my water almost on a daily basis.
1Is this a common problem with E46 BMW and how often should one refill the coolant/water
2 Could this have caused the damage and eventual leakage?
3 Is an aftermarket water bottle ok to replace with?

September 16, 2013
  Followup from the Pelican Staff: Pressure test the cooling system, replace any parts that are leaking. Fill the cooling system and bleed it. Make sure all the air is out. Check to make sure the thermostat I and the fan clutch are working correctly . I would grab a repair manual. It will list the special tools and each step of the procedure. Give our parts specialists a call: 1-888-280-7799 They will help you find what you need.
- Nick at Pelican Parts
 
tokzin Comments: You guys rock. I hav a 318is dolphin it moves fine but I've noticed on the oil cap a bit off oil and water mixed together but the gage did not climb up what could be the problem
September 12, 2013
  Followup from the Pelican Staff: It could be from the oil separator, check it to make sure it is functioning properly.
- Nick at Pelican Parts
 
Smith Dan Comments: What if my 96 z3 1.9 runs too cold, while moving heat only goes up a quarter of the way. Idle it warms up to normal in the middle and stays. Thermostat issues??
September 11, 2013
  Followup from the Pelican Staff: It could be a thermostat that is stuck open, or a fan clutch that doesn't disengage. - Nick at Pelican Parts  
Jase Comments: Hey I have a 1988 325i I have recently blown my throttle body cover gasket and the car started to over heat temp. Gauge went right up to the red.. Not past or on the red just right before it so I pulled over ASAP and it is now replaced . NOW!! At idle sometimes it will climb in temp starting cold then it will slowly climb to middle then slowly climb more towards hot what's the order I need to check ?? Thanks !!
September 10, 2013
  Followup from the Pelican Staff: Check that your coolant level is correct and there is no air trapped in the system. If you didn't replace the thermostat, it may be faulty. You are going to have to find the original cause of the overheating. I would also pressure test the cooling system. If the system does not hold pressure and there are no external leaks, you may have a faulty head gasket. - Nick at Pelican Parts  
Tokzin Comments: I hav a BMW 318is it has a hard start and sometimes jurcks on the free way what could it be and also how can I change my starter bendix my car is a automatic
September 6, 2013
  Followup from the Pelican Staff: Hard starting could be caused by many things, start with the basics, fuel pressure, volume and quality. check for a vacuum leak and so check for any fault codes. this will give you a place to start. Check out our tech page for an article on changing the starter. grab a repair manual. It will have the procedure, special tools and torque specs.
- Nick at Pelican Parts
 
mitchy Comments: i have a 2003 BMW x5 3.0 over flow tank cracked so i just replaced over flow tank. still hot so replaced thermostat. upper radiator hose still hot and lower hose cool to touch. would it have to do with water pump?
September 5, 2013
  Followup from the Pelican Staff: Could be water pump, check for flow at coolant tank, also make sure cooling system has no air in it and the thermostat is opening up.
- Nick at Pelican Parts
 
Yenzee Comments: Hey, so I have a 1991 m42 318is e30 that recently developed an overheating problem at idle. I replaced the thermostat in it not too long ago and had no problems for a while but, just the other day when I went to school, I was sitting idling waiting for a spot to open up when my car began to over heat. I could hear my rad. fan turn on to cool the coolant but the needle kept climbing before it went too far I turned my heater to full blast and that brought the needle right back down to where is should be. I've checked the coolant level and that's all good and I know the rad. fan works too. I've also noticed as I come to a stop with the heater on my coolant temp. will go down and then when I get going over 50mph hot air will stop blowing out of the heater. This leads me to believe it could possibly be the thermostat that's faulty but, I just wanted another opinion. Thank you in advance.
August 26, 2013
  Followup from the Pelican Staff: This could be a faulty thermostat or water pump. Check to see how long it takes for your engine to warm up. Once you confirm it is warming up, check that the cooling system has good flow. The vbleeder hole int he reservoir should have a stream of coolant flowing at idle. If not, the water pump may be faulty or air is trapped in the system. - Nick at Pelican Parts  
KayNickG Comments: Me again, if it's overheating, where can i go to get this checked and for how far can i safely drive it, and do you know how much it should cost to fix this.
And thank you very much Nick
August 22, 2013
  Followup from the Pelican Staff: You can take it to a repair shop, expect to pay about an hour labor to have the cooling system tested. - Nick at Pelican Parts  
KayNickG Comments: Hello
i don't know much about cars but my 96 bmw 318i just started making a hissing sound. And it's getting kinda hot, and when driving, i can feel it go and then stop kind of. Im in college and i can't afford to waste money can you tell me what's wrong.
please and thank you in advance.
August 21, 2013
  Followup from the Pelican Staff: Hard to guess at a sound without hearing it. With that sdaid, if you have hissing, steam and the engine is getting hot, it could be overheating. I would check the cooling system for leaks. - Nick at Pelican Parts  
chris Comments: Followup from the Pelican Staff: Does coolant come out of the bleed screw when you open it. Be careful the coolant will be hot. Did you change the thermostat? If that is stuck closed the coolant will not circulate. - Kerry at Pelican Parts

Well i let the car run the other day thinking i missed an air pocket, when i open the bleed sscrew, it does come out when i have the coolant topped off, but it only comes out a bit, it does not bubble , i am going to take the thermostat out tomorrow and test it

thanks
christian
August 12, 2013
  Followup from the Pelican Staff: Please let us know what you find with the thermostat - Kerry at Pelican Parts  
chris758 Comments: installed new water pump , fan and rad, put new coolant in, , car was fine, all the raditor hoses have no pressure?? is that normal? the car only warms up too the second line.. and the head isnt warm,, is there still an air pocket in the coolant.. or is something else wrong??

thanks
chris
August 10, 2013
  Followup from the Pelican Staff: Does coolant come out of the bleed screw when you open it. Be careful the coolant will be hot. Did you change the thermostat? If that is stuck closed the coolant will not circulate. - Kerry at Pelican Parts  
Thor Comments: I have a 1997 328i I just replaced my thermostat and housing. Did everything here and went for a spin round the block and my engine overheated.. It never overheated before.
July 31, 2013
  Followup from the Pelican Staff: Did you bleed the cooling system? There could be air trapped inside it. - Nick at Pelican Parts  
Big A Comments: I have a 96 318i 4 cylinder. Recently ran the car hot and cracked resevoir on side of radiator. Replaced radiator and top and bottom hoses. Car runs at nomal temp now but I have to add about a half a gallon of water every 4 to 5 days, I see no leaks on groud or when idling. Any ideas?
July 20, 2013
  Followup from the Pelican Staff: You could have a faulty head gasket. I would pressure test the cooling system. If the system will not hold pressure and there are no external leaks, this indicates an internal coolant leak. - Nick at Pelican Parts  
tim Comments: BMW 2001 x5 Air Temperature Sensor intake FACET temp sender sending unit. Where is it located? The parts guy said it was on the filter box, took the box out and still did not find it. Do you have a picture of the location?
July 18, 2013
  Followup from the Pelican Staff: it should be mounted near the intake manifold, the rear runners. - Nick at Pelican Parts  
johan Comments: My e46 thermostat top radiotar hose very hot bottom not that hot radiotor fan switch on and temp gauge shows half is ther any modifications on thermostat that I can do to let engine run cooler
July 16, 2013
  Followup from the Pelican Staff: If the temperature gauge shows half way your engine is running at the correct temperature. You don't want it too cold because it affects the fuel injection. You may be able to get a lower temperature thermostat to drop it a few degrees but it sounds like you're okay - Nick at Pelican Parts  
sean Comments: I have a 1997 328i, 116K, just blew a head gasket. Do any of the pour-in systems like K and W or Thermaweld work?
July 15, 2013
  Followup from the Pelican Staff: Only very temporary. It's hard for the head gasket to hold in combustion pressures let alone these liquid sealants - Nick at Pelican Parts  
Zack Comments: How would I fix that thoe or check the codes or et it put of limp mode with out spending a whole lot of money
July 7, 2013
  Followup from the Pelican Staff: Most chain auto parts stores will clear codes for you for free. That should get it out of limp mode but the same problem that put it in limp mode will probably happen again. - Nick at Pelican Parts  
Chad Comments: I am replacing my thermostat on a 2001 530i E39 M54 one of the 3 bolts broke so now I need to get a new one, but I cannot find a part number or diagram with the screws in it. Any ideas? the bolt says 8.8 ESKA on it. I know that 8.8 denotes the quality level in the metric system and ESKA is the original manufacturer it is a 10mm head
July 4, 2013
  Followup from the Pelican Staff: Give our parts specialists a call at 1-888-280-7799. They can help you find the right part. - Nick at Pelican Parts  
Zack Comments: I have a 2002 bmw 525i an when I first start it an drive after not been cranked in a couple of hours it will act like it does not want to go or when I push the gas also when I have my air on or with it off it doesn't over heat but it will do something with the transmission an put it in fourth gear an I have to cut it off wait a minute an cut it back on I think I have a bad coil pack an it also burns oil really bad an I have tried to go with thicker oil but it does not help and I always use full synthetic like its suppose to
July 1, 2013
  Followup from the Pelican Staff: I would start by checking the DME and trans ECU for fault codes. If the transmission is starting in fourth gear, a fault code will be set. This is limp mode. - Nick at Pelican Parts  
Tt Comments: Hi, my BMW 528i only runs hot After i am sittin still for minutes when i take off the temperature goes back on the blue..What do i do
June 18, 2013
  Followup from the Pelican Staff: Start bt checking your coolant level and confirm there are no leaks. Then check if you thermostat and cooling fans are operating properly. - Nick at Pelican Parts  
teerex Comments: I have v1997 bmw 323i that keep running hot i have changed every part that deals with the cooling system and still runs hot im lost
June 3, 2013
  Followup from the Pelican Staff: First thing is to check if there is any air in the cooling system. Try to bleed it again. Then check that the thermostat is allowing coolant to flow through the engine once operating temp is met. If all of your cooling system componenets are functioning correctly, you may have a faulty head gasket. The bext way to test for a faulty head gasket is to check the cooling system for C02. - Nick at Pelican Parts  
Gray Comments: Hi!
I have a 2003 330i- I just replaced the radiator, water pump, hoses, thoermostat with housing and am almost done.
The sensor in the old thermoostat had melted so I have replaced the connector with a bosch 2 wire pigtail.
The wires on the pigtail are both white.
Can I wire it either way or is there a specific polarity for this sensor?
Thank you!!
June 1, 2013
  Followup from the Pelican Staff: I would reconnect the wires to the orignal terminals. The red/white wire connectos to erminal 1 at the thermostat, the greay/brown to terminal 2..- Nick at Pelican Parts  
angelina Comments: Its a 2006 nick @ pelican parts. it also sounds like it's about to cut off when idle also.
May 7, 2013
  Followup from the Pelican Staff: Locate your oil leak by folling the path of the oil to the source. The area witht he leak will have fresh clean oil stains. If the leak is a big mess, try cleaning the engine, then rechecking for the area of the leak. - Nick at Pelican Parts  
angelina Comments: My 525 has a oil leak, does this mean i need to get the valve cover gasket replaced. were else could it be leaking from?
May 2, 2013
  Followup from the Pelican Staff: What year is your 525i? It could be the oil filter stand or a sensor near the top of them engine. - Nick at Pelican Parts  
ladybmw Comments: I have a 2007 525i. The engine temp went up, i add water because the coolant was low. shortly after that the heater stopped working. it keeps running hot, unless i let it warm-up with the resevior cap off. now the belt broke. Any suggestion on what could be wrong.
May 2, 2013
  Followup from the Pelican Staff: This could be a faulty head gasket. Check operation of the water pump and thermostat. If they are functioning normally, check the head gasket. My preferred way to check it is to check the cooling system for Co2. - Nick at Pelican Parts  
tuffie Comments: I have a 1993bmw 525i with an overheating problem . Ivr changrd the radiator, thermostat and the water pump is fine. The coolant didnt gey in the oil. And the sensor was. Replaced . It is still running hot.plz. help.
April 23, 2013
  Followup from the Pelican Staff: Check if the coolant is flowing, you should be able to see it flowing in the reservoir. if it overheats under load, you may have a bad head gasket. I would pressure test the cooling system. - Nick at Pelican Parts  
jack Comments: Nick, thanks for your response to my question of March 31. The BMW tech did a pressure test. No sign of any leak. Determined that because the car only leaked coolant after cool down, problem was the water pump. Replaced water pump. No more leak. Temp gauge problem was due to an air bubble caused by the leak.
April 15, 2013
  Followup from the Pelican Staff: Glad to hear they found it. - Nick at Pelican Parts  
Jmccabe8 Comments: Have a 98 BMW Z3. Thermostat replaced by BMW garage as car was not warming up. Thermostat was stuck open.
Car now has a small leak in cooling system. Drips only appear after car has been parked overnight. Temp gauge will stay on normal, intermittently run up to the red but comes right back down. Can you please help diagnose the problem. Thanks, Jack
March 31, 2013
  Followup from the Pelican Staff: I suggest pressure testing your cooling system. If you just had a repair performed, visit the mechanic and ask him to pressure test it for you. - Nick at Pelican Parts  
kevin Comments: Does anyone have any ideas on how to replace a thermostat on a 2004 325 ci ?
January 22, 2013
  Followup from the Pelican Staff: This tech article should help: http://www.pelicanparts.com/BMW/techarticles/BMW-3-Series-E46/30-WATER-Removing_Your_Thermostat/30-WATER-Removing_Your_Thermostat.htm - Nick at Pelican Parts  
scoota Comments: Hy I just changed my thermostart on my bmw e36 but still blows warm air inside
January 20, 2013
  Followup from the Pelican Staff: If the air temperature isn't changing inside the cabin, the problem is related to your HVAC controls, not he themrostat. - Nick at Pelican Parts  
CMac Comments: Hi, I have a 1997 318i that had a new thermostat and I've gone through all the bleeding etc. what I have now is a rough idle and a temp gauge straight up to red. Odd thing is the left side of the radiator is hot while the right side clear plastic container is cold. Why?
January 19, 2013
  Followup from the Pelican Staff: If the engine was running at normal temps before replacing the themrostat, you still have air trapped in the system. Try bleeding it again.- Nick at Pelican Parts  
TC in Atlanta Comments: Two weeks ago, I changed the o ring on the coolant temp sensor and refilled with coolant. I've discovered that I have codes Peake tool table 19/7b for thermostat problem. Do I need to completely drain the coolant or can I get by with half or so?
December 17, 2012
  Followup from the Pelican Staff: Just try bleeding the cooling system first and that should take care of your code - Nick at Pelican Parts  
srcn476 Comments: just replaced the engine in my 93 318 is , im having problems with my temp gauge, it doesnt work. changed the sensor, still not working, upper radiator hose is hot ,lower hose is cold, im thinking sensor should still work if thermostatis stuck closed, any ideas?i have bled the radiator twice now. fuses in engine compartment all good. thanks
November 30, 2012
  Followup from the Pelican Staff: Usually if you unplug the sensor electrical connector the gauge should move all the way in one direction. Then ground the wire you've unplugged and the gauge should move all the way in the other direction. This is how you check for a bad gauge - Nick at Pelican Parts  
Fitz Comments: Wayne, I replaced all components to the cooling system on my M3 E36. Looks like I put in all correct. Sucked in 1gallon of BMW antifreeze mixed with 1 gallon of distilled water. Is that enough or do I need to add more? The engine operates at normal temperature but will not warm up in the interior the air stays luke warm, I turned on the AC and it gets cold quick. Do I have a bad thermostat or not enough coolant?
November 2, 2012
  Followup from the Pelican Staff: Your thermostat may be stuck open or the duovalve/heater valve may be stuck closed. What is the coolant level in the reserve tank? - Nick at Pelican Parts  
Vick Comments: I have an issue with my bmw 525i 2004 I change day whole thermostat housing and it's only been a week and I think it messed up again
August 31, 2012
  Followup from the Pelican Staff: Sorry to hear that. How did it mess up again:? - Nick at Pelican Parts  
Earl Comments: If I was going to install a sensor for an aftermarket water temp gauge, where on the thermostat housing should I tap/drill?

Thanks in advance.
August 9, 2012
  Followup from the Pelican Staff: The bottom half otherwise you will see the gauge fluctuate as the thermostat opens and closes - Nick at Pelican Parts  
Smarter Comments: Using ANY silicone, especially that large of an amount is ridiculous. This is why I never follow any of Pelican's "technical articles".
The BEST way to install a thermostat housing is to use a new OE BMW gasket with a THIN film of grease rubbed all around it.
If you know what you're doing, there will be no leaks.
July 4, 2012
  Followup from the Pelican Staff: You obviously didn't actually read the article - the amount of sealant used is to fill in the electrolysis holes that were worn in the cylinder head. If your head has this amount of damage done to it and you don't use some type of sealant, then you will be in trouble. If you're going to comment on an article, I would appreciate it if you actually read it first. Thanks... - Wayne at Pelican Parts  
onlyoneluke Comments: Hi, i have a BMW 318i 1993, when i start it while still parked the temperature guage shows normal and when i just drive it within 200meters the temp guage gooes to red. What could be the cause of this problem? Please i need your help.
April 26, 2012
  Followup from the Pelican Staff: You could have a stuck closed thermostat, a bad water pump or a back head gasket. You're going to need to check this stuff out - Nick at Pelican Parts  
kowboy Comments: we have 1 1998 318I 4 door, the temp gauge stayed at normal but the car was smelling hot, you know like hot antifreeze, i replaced the thermostat and housing, no leaks, the water still gets hotter than hell, the top hose gets piping hot, the bottom hose stays cool. the tempguage finally went into the red, what could this be, one guy says it may be a cracked head, can anyone help. the cooling fan only comes on when the ac is on
March 14, 2012
  Followup from the Pelican Staff: It could be a cracked head or bad head gasket but it could also be a bad water pump where the impeller fell off so the water is not circulating or a thermostat stuck closed blocking circulation. - Kerry at Pelican Parts  
Yakima Jim Comments: 2002 330 After seeing signs ofleaking coolant, the local BMW shop former dealer told me the water pump was leaking. They replaced the waterpump and thermostat. Now I have no heat for about 3-5 miles depending on outside temp until temp guage reaches normal, at which time the low coolant light comes on and the heat finally starts to work. Previously I had heat in about 1 mile. Did they screw something up? System pressure tests good 3 hr. Coolant level is good at filler cap.
March 8, 2012
  Followup from the Pelican Staff: Try opening the bleed screw while the car is warming up. You may have an air pocket. Also look at the flow in the coolant expansion tank. - Kerry at Pelican Parts  
fefui9901 Comments: I have a 1997 BMW 528i and it is overheating. The water is not flowing to the radiator and is just not circulating.I really want to get back to driving this car. Please help.
March 6, 2012
  Followup from the Pelican Staff: While you could have a bad head gasket or a cracked head you probably have either a bad water pump or a thermostat that is stuck closed. Try replacing those first - Kerry at Pelican Parts  
yandizt Comments: I've just replace thermostat for my E36 323i year of 1997, but I used 71 degree thermostat. What is the standard temperature? is it 92 degree? what if the consequence if I used below standard thermostat 71 degree?
February 11, 2012
  Followup from the Pelican Staff: A lower temperature thermostat will allow it to open sooner and the car will run cooler. This may cause you engine electronics to run richer. Typically lower thermostats are used for towing since the extra load will increase engine temperature. - Kerry at Pelican Parts  
Mervy Comments: HI Wayne
I have a 2004 BMW 318ti and when i drive a short distance
water is overflowing from the water bottle and it is hot.
How can i solve this problem
January 31, 2012
  Followup from the Pelican Staff: Sounds like your vehicle is overheating. Check the coolant level and be sure there is not air trapped within the cooling system. Check operation of the thermostat, water pump. - Nick at Pelican Parts  
Happy Pappy Comments: Great pictures,
I have replaced the thermostat but I'm leaking coolant underneath now which is falling on the fan belt, not sure where its coming from. I have picked up the comment on the arrow of the thermostat and I did not check that is this important, do we really need a thermostat in my 1990 BMW?
The thermostat housing is very hot but temp gauge is around the half way mark
Thanks

Mike Pappas
January 21, 2012
  Followup from the Pelican Staff: I suggest leaving the thermostat installed, you do need it for your vehicle to rubn best.

You could have air trapped in the system, causing the overheating. The leak could be a misaligned thermostat. - Nick at Pelican Parts
 
Gwen Comments: I had my BMW 325XI thermostat replaced as well as the housing and sensor a year ago, it has gone bad again. How long should a new thermostat last?
January 18, 2012
  Followup from the Pelican Staff: A replacement thermostat should last as long as the original one it replaced. For example, if the first one lasted 60,000 miles, expect the new one to last the same amount of time. - Nick at Pelican Parts  
ivan Comments: reply to SB.....it sounds to me like a FSRfinal stage resistor is bad. search for that problem
December 22, 2011
  Followup from the Pelican Staff: Thanks for the input on this one. We appreciate the help. - Nick at Pelican Parts  
SB Comments: 12/9/11!!!!HELLO PLEASE HELP i have a 1998 528 i BMW... air blows out of the vents full blast when it wants to when the car is on or off yes on or off with the key not even in the ignition. anyone ever heard of this happening before please advise. thank you
December 10, 2011
  Followup from the Pelican Staff: Sounds like a faulty final stage resistor for the blower motor. - Nick at Pelican Parts  
Russouw Comments: Hi Guys, my 2002 BMW 318i has an overheating problem and this normally happens during peak traffic when the car is moving slow. when i am driving constantly on an open highway the temperature remains normal. the coolant levels are normal. What might be the problem?
November 24, 2011
  Followup from the Pelican Staff: Your cooling fan could be faulty. Check that the viscous fan and auxillary fans are working properly. - Nick at Pelican Parts  
Tony Comments: I have a 2004 BMW 318i Manual Sports which my son uses.The other day he got to his friend's house and the coolant warning light went on and the engine overheating.His friend's father found that the coolant tank had a crack in.This was replaced but then the radiator fan did not work and no water circulation.
They seem to think it is the thermostat that is blocking the water flow and are having another friend who is a BMW mechanic to remove the thermostat and let the car idol without it.I do not know if this is advisable.We live in South Africa.
My view is that it could be a water pump problem as well.I really do not know.Any ideas?
Tony
November 13, 2011
  Followup from the Pelican Staff: Check that the water pump is working. That would be the first place you want to look. The crack in the reservoir mayh ave been a product of overheating, not the cause. - Nick at Pelican Parts  
ahmed Comments: hi every one
am having bmw 318i with over heat problem.radiator,fan,waterpump,engine cooler is fine but my car still having the same problem, any help plizz, thanx
November 5, 2011
  Followup from the Pelican Staff: Check that the head gasket isn't fault. Pressure test the cooling system. If it does not hold pressure and there are no external leaks, the head gasket may be faulty. - Nick at Pelican Parts  
mzjay Comments: Coolant began to drip from behind the battery of my BMW 318ti. The heater still heat. Does the thermostat need replacing or just the hoses?
October 24, 2011
  Followup from the Pelican Staff: I would pressure test the cooling system. This will help to isolate the leaking area. Replace any component that is leaking. - Nick at Pelican Parts  
grease monkey Comments: Hi,I hav a 99' 323i E46 BMW,iv changed the thermostat,water pump,new head gasket,helicoiled the block and new radiator and upper coolant hose and its still overheating...really not sure what to do...any suggestions?
October 13, 2011
  Followup from the Pelican Staff: If the coolant level is OK and there is no air trapped, check for proper cooling system flow. If low is OK, you still may have a head gasket issues. I have not had luch helicoiling the blocks on E46 models, a replacement engine is usually the best fix. Pressure test the cooling system. If it does not hold pressure and there are no external leaks, you may have a headgasket leak.- Nick at Pelican Parts  
Sweetnlow Comments: I just had the thermostat replaced in my 1998 BMW Z3 1.9 by my husband. I downloaded your instructions on how to do that for him since he is not familiar with BMWs mostly TRUCKS! LOL

Anyway, it was a snap, thanks for the great information. However...the car is still running hot. Any suggestions on what I should do?
October 8, 2011
  Followup from the Pelican Staff: Check that there is no air trapped in the cooling system. If it is properly bled, check operation of the water pump.- Nick at Pelican Parts  
plug Comments: 1995 525i does it have a coolant bleeder screw and if so where is it located?
September 2, 2011
  Followup from the Pelican Staff: Yes, it could have a total of two. One on the coolant reservoir and one on the thermostat housing. - Nick at Pelican Parts  
countrygirl Comments: Hello Everyone! I am new and stumbled upon your site. Your site has been extremely helpful. Thank you Tech articles and Everyone else for helping me with thermostat issues. Thanks again everyone! DDolin
August 22, 2011
  Followup from the Pelican Staff: Thanks for the feedback. Glad we could help. - Nick at Pelican Parts  
KiKi Comments: I was driving my 93 BMW 318is and the check engine light came on and then I saw my temp gauge going towards Hot. Coolant added this morning. Ran car about 13 minutes. Temp gauge went over to hot. Help...
July 29, 2011
  Followup from the Pelican Staff: if you had to add coolant, there may be a leak. I would pressure test the cooling system and repair any leaks. It might be a good idea to replace the thermostat too if the engine was overheated. - Nick at Pelican Parts  
1998M3dude Comments: Just replaced my thermostat and housing. I replaced old housing with Aluminum housing and was getting a small leak still. I put gasket sealant all around the surface of the housing and still had a leak. Replaced it with the old housing and put new gasket and sealant and still have a leak...Any advice?
June 28, 2011
  Followup from the Pelican Staff: You should not use sealant on a surface that is sealed with a rubber gasket. Remove the thermostat and inspect the sealing surface on the engine for pitting or corrosion. If the surface isn't in good shape, the thermostat will not seal. - Nick at Pelican Parts  
BillM Comments: Sorry, just saw a post from someone else asking the same question no arrow/bleed hole in thermostat. Mine is also a "Vernet" branded part, thought I would share. Thanks, Bill
May 10, 2011
  Followup from the Pelican Staff: Got it, thanks. - Nick at Pelican Parts  
BillM Comments: Quick question - do all thermostats have an arrow or weep hole? I am installing an 80C in E36 M3 and don't see either?
Thank you, Bill


Sorry, just saw a post from someone else asking the same question no arrow/bleed hole in thermostat. Mine is also a "Vernet" branded part, thought I would share. Thanks, Bill
May 10, 2011
  Followup from the Pelican Staff: No, not all of them. You would be the best judge if your s has one, being you have it in hand. I think I have seen Vernets without a bleed hole. - Nick at Pelican Parts  
safi Comments: Hi,
I have a BMW x5 2001, The coolent temp. is always law and the arrow sign is below the middle I just wonna know if there is a thermostat lower than 97 degree or there is a malfunction in the thermostat.
May 4, 2011
  Followup from the Pelican Staff: The thermostat on your car does not measure the exact temperature. Think of it more as a warning light. If it is not running hot or overheating, it is probably running normally. If you are concerned, I would suggest checking the actual coolant temp with a themrometer. - Nick at Pelican Parts  
juanito Comments: I HAVE A PROBLEM WITH MY 97 328I CHECK ING LIGHT ON,CODE P1519 SAY CAMSHAFT POSISION,I REPLASED BUT THE LIGHT STILL ON . THE DISCRIPTION ON THE SCANER SAY IDLE SPEED CONTROL AUXILIAR MALFUNTION .
DO I NEED RETIMMING THE INGENNE
April 28, 2011
  Followup from the Pelican Staff: P1519 is a camshaft actuator fault. This could be a faulty VANOS actuator or VANOS unit. - Nick at Pelican Parts  
Reed Comments: Hey, I just bought an aluminum thermostat housing that came off a 1992 non-vanos m50, will this work on my 1994 VANOS m50?

Thanks
April 19, 2011
  Followup from the Pelican Staff: it should. I would just remove the old one and compare the two to be sure. - Nick at Pelican Parts  
Alex Comments: Hi,
I have a 328i and was not able to loosen the fan clutch nutyes, I know it has left handed thread. I used all the recommended tricks except for the bmw fan tool, which I couldn't find anywhere. So, it was actually quicker and easier to remove the radiatorwithout removing the fan or the plastic shroud to get the clearance I needed for a ratchet, and my hand.
April 17, 2011
  Followup from the Pelican Staff: If you simply put "fan removal tool" into our search engine, it will come right up. Here's a direct link: http://www.pelicanparts.com/bmw/catalog/shopcart/BE36/POR_BE36_TOLtol_pg9.htm#item58 - Wayne at Pelican Parts  
fgs Comments: Figure 6 comment points out the importance of putting the "arrow or bleed hole" at the uppermost point. There is no "arrow or bleed hole" in your photo and there is none on my 88C Vernet thermostat.
Should one drill a bleed hole or is this an error?
March 29, 2011
  Followup from the Pelican Staff: I'm not sure why there isn't an arrow or hole in the photo, but the replacement ones should have one, and it should point upwards. - Wayne at Pelican Parts  
CarlosK Comments: Hi, I own a BMW 316i E30. It had overheating problems so i did all the fixing new thermostat, new fan clutch, new water pump, new radiator, new sensor that goes into engine. Today I started the engine and after 2 minutes water temp gauge needle went to red. Obviosly engine was not hot, what can it be?. Thanks
March 21, 2011
  Followup from the Pelican Staff: If there is an air bubble somewhere in the engine and water is not circulating to the heads, then you will get overheating problems like you have here. I would try bleeding the cooling system 3-4 times to make sure that you get all of the air out. - Wayne at Pelican Parts  
Nick Comments: I have a '97 1.9L Z3 M44, build date 10/96. It currently has a plastic thermostat housing? Will it be possible to upgrade this to an aluminum housing part #11531722531?
February 27, 2011
  Followup from the Pelican Staff: The information that I have on that part number seems to indicate that it's only for the six-cylinder engines, and not the four cylinders, so I don't think it would work. - Wayne at Pelican Parts  
veco Comments: I have a i325 bmw and its overheating. I suspect that its the thermostat can I removed and leave the car without it?
February 13, 2011
  Followup from the Pelican Staff: I've heard of a few people removing the thermostat altogether. In general, I don't recommend it, as the car needs to get up to proper operating temperature as soon as possible. Removing the thermostat will cause the car to run cold for a long period of time. This would be especially painful in cold climates. I recommend simply replacing the thermostat with a good quality one that works. - Wayne at Pelican Parts  
BobbyT Comments: Hi guys,
Thanks for the great write up! Quick question. My '99 328is is throwing an "insufficient coolant temp to operate in closed loop mode" code. I replaced the coolant temp sensor but the code hasn't cleared, and now the check engine light is coming on and off, usually on when very cold, and off when slightly warmer. Also, the car does not reach normal operating temp anymore based on the gauge and the heat is sometimes not so warm. At this point I'm thinking my T-Stat has to be stuck open. Any thoughts?
January 19, 2011
  Followup from the Pelican Staff: I would tend to agree with you on this - it sounds like your thermostat may be stuck open. I would check out the radiator hoses on your radiator to see if they are hot / warm when the car has been running for a while. - Wayne at Pelican Parts  
Benp Comments: I have a e36 1993 325i. Temp gauge stays very consistant while driving and idle but when at idle the car stops blowing hot air almost immeadiatly. Is this just a bad thermostat?
January 18, 2011
  Followup from the Pelican Staff: COuld be a bad thermostat or a faulty water pump, if circulation drops at idle due to RPM, the coolant in the heater core will cool off. - Nick at Pelican Parts  
cms Comments: a part house sold me the wrong thermostat.
i have a 99,323ic i installed a 192F 88.8C
i find out it should be 198F 92C for this model
what kind of problem will i get if i leave that part in
thank you...
November 22, 2010
  Followup from the Pelican Staff: It will run just slightly cooler and I don't think it will cause any major problems for you. - Wayne at Pelican Parts  
daveb Comments: found the problem. System had air. I put the cap back on before the restart. Should have left it off for the air to bleed... Running well now....
November 21, 2010
  Followup from the Pelican Staff: Thanks for the follow up. We appreciate it. - Nick at Pelican Parts  
Daveb Comments: Put a new thermostat in E30 M3. Car is running hot, and does not appear that the thermostat is opening top of radiator is hot, bottom is not. Air in system or faulty new thermostat?
November 20, 2010
  Followup from the Pelican Staff: If the top of the radiator is hot, then the thermostat is working (both top and bottom would be cold if the thermostat was stuck closed). Sounds like there might be clogs in the radiator. Or, the radiator may be working fine (hot on top, cold on bottom is also normal as the coolant cools in the radiator itself). I would remove the radiator and flow test it and/or replace it if the car is running hot (if the car is running hot, then you probably have a clogged radiator and/or a bubble in your cooling system). - Wayne at Pelican Parts  
Samir Comments: I have BMW 1998 528i, the temp went way up while I was sitting idle, the minute I drove the temp came to normal. 6 months later the temp went up slightly while gasing the car, temp came down as soon as I drove. THe pump was changed 2 years ago when broke on the highway. any idea what it could be? I really do not trust driving on highway any longer.
November 12, 2010
  Followup from the Pelican Staff: It could be a small leak in your cooling system that is causing it to lose pressure, and then may be creating an air bubble. I would start by rebleeding the cooling system and see if that fixes the problem. See the article in this section for details on how to do that. - Wayne at Pelican Parts  
TonyM3 Comments: o2 sensor was playing, all fixed now.
thanks
October 31, 2010
  Followup from the Pelican Staff: Thanks for the follow up. We appreciate it. - Nick at Pelican Parts  
Daveb Comments: Figured it out. Needed to whack wrench with a mallet to break them free. Looks like the copper washer corroded a bit and froze it. Mistake I made was using a socket on it with constant pressure.... Goofy design, not sure why BMW ship with holes plugged....
October 31, 2010
  Followup from the Pelican Staff: It's done that way because not all the cars have a sensor in that area. - Wayne at Pelican Parts  
daveb Comments: question. on the E30 M3, the thermostat ships with sensor holes plugged. the plugs seem impossible to remove. what am i missing and how do i get them out?
October 28, 2010
  Followup from the Pelican Staff: I'm not sure, if you need the sensor there, you should be able to remove the plugs. Maybe just use a bigger torque arm to get more leverage? - Wayne at Pelican Parts  
TonyM3 Comments: Hi, I have a 6 cylinder e36 320i sedan which starts and idles ok smoothly. The car bogs and loses power at low revs to the point where the car barely accelerates. You have to put the foot to the floor and then it starts to accelerate still not overly quickly. These problems are worse when the car is warming up, however even when the car is hot it still has significant flat spots at low revs.
I disconnect the AFM runs heaps better on low revs and when I put the foot down goes but not as it should, I think they saying its kind a Limp Mode and ECU adjust some constant fuel to prevent stalling when afm is disconnected
Things done since then as follows.
-New fuel pump & fuel filter $160
-New pressure regulator $120
-ignition coils from USA $160
- AFM swap
- Crank sensor check
- Cam sensor check

Things that i want to check next are: coolant temp sensor and oxygen sensor.
Can you please advise for solution, because it’s really giving me a hard time?
October 27, 2010
  Followup from the Pelican Staff: You didn't mention if you'd pulled any codes out of the ECU to see if the computer was giving any hints? - Wayne at Pelican Parts  
rob Comments: @mack

Overheating could be a problem with the gasket. If you take it into a place that does radiators they can do a test with a liquid which changes colors in the presence of exhaust fumes.
October 18, 2010
  Followup from the Pelican Staff: Good advice. Check the cooling system for co2 is one of th best ways to check for a faulty headgasket.

Thanks for the input on this one. We appreciate the help. - Nick at Pelican Parts
 
mack Comments: could ongoing overheating be a head gasket issue? sounds like you've tackled everything else so far.
September 14, 2010
  Followup from the Pelican Staff: Thanks for the input on this one. We appreciate the help. - Nick at Pelican Parts  
Jim Comments: Pelican Staff:

I am having an identical problem with my '83 320i that "Abz_009" is having. Have replaced radiator, pump, thermostat, flushed system. Still runs hot at idle whether im in neutral doing 70 or stop and go. Cools down at high revs. Ive also re-adjusted the heater valve so that now closes fully. These changes have marginally improved on the problem. Please let me know what you think

Jim
April 28, 2010
  Followup from the Pelican Staff: Sounds like significant air bubbles in your cooling system that are still there. I would change up your coolant bleeding procedure. I found I had to try a few different things on my E36 to get it correct, see my article here: http://www.pelicanparts.com/bmw/techarticles/E36-Coolant_Flush/E36-Coolant-Flush.htm I'd bet you a dollar that there's a big ole air bubble in there somewhere that is causing heat pockets to occur. That's really the only thing if you've already replaced almost everything else. - Wayne at Pelican Parts  
Abz_009 Comments: Hi I have a BMW 316i and the engine keeps overheating. Spent loads trying to correct but noone has been able to fix, replaced thermostat, biscus fan and bled the system no luck. Temp only reduces when the car is revved. My current mechanic believes all the new thermostats dont open quickly enough and i need an original part, i find that strange and think it might be something else. He refuses to budge on his opinion and is convinced its waterflow. I dont have much more to spend to help solve this so any help would be great. Any ideas what i can try next?
April 2, 2010
  Followup from the Pelican Staff: If the thermostat is openeing, even a little late, it should not overheat. I would check the cooling system for exhaust gas (co2) to test if the head gasket is faulty. - Nick at Pelican Parts  
...bill Comments: Hi. 94 325iC. Classic radiator neck failure occurred. Luckily caught it 10 miles from home. Purchased radiator, tank, hoses, thermostat, etc. from Pelican. Flushed and installed everything with little drama. Used 50/50 bmw coolant, and was careful to bleed out air.
After two weeks, it takes longer and longer to reach operating temp temp needle sits below center for 10 min or so never did this pre-rad failure. Heat is pretty crummy and temp falls off during idle.
1. I believe I purchased an 88 degree thermostat. Is that too cold? My ambient is around 40-50F.
2. Could my thermostat be faulty?
3. Is there anything else that could be going on?

Thanks,
...bill
March 5, 2010
  Followup from the Pelican Staff: The thermostat could be stuck open. Check to see if the thermostat is allowing coolant to flow immediately. All the hoses will be the same temp when warming up.- Nick at Pelican Parts  
Austin Comments: Hi,
I have a 92 325is and after the last run at my previous autocross the plastic radiator coupling burst causing coolant to spew everywhere. i linked it back up in an attempt to drive it home but to no avail as i had to pull over to a gas station because it popped off again and caused another spout of overheating. we replaced the radiator and the thermostat again the water pump isnt making any strange noises as far as we can tell. there doesn't seem to be anything at all pumping through the top coolant hose. Also i should mention there's no arrow on the thermostat to indicate direction it should be pointing. It just wont stop overheating no matter what we try, bled the system did a near perfect 50/50 coolant combo. any advise?
Please Please help
Many Thanks
January 22, 2010
  Followup from the Pelican Staff: I would pressure test the cooling system. If the system does not hold pressure and there are no external leaks, you may have a faulty head gasket. - Nick at Pelican Parts  
Jim Comments: I have 1996 318ti, replaced the thermostat that was stuck open. Car ran cool before replacement and with some blower heat. Now it reaches operating temp, stays there for a while and then overheats. Plus I am getting no blower heat. now.
January 19, 2010
  Followup from the Pelican Staff: Sounds like air is trapped inthe sooling system. Try bleeding it again. - Nick at Pelican Parts  
Gramps2 Comments: Bought the thermostat from Pelican Parts for a 2004 BMW 330CI and got to the step to remove the fan and got stuck without the "fan removal tool". I come from a family of having to do for yourself and following in that tradition, made the tool out of a 1/8" x 1.5" steel strap. Cost me less than $10 and about 1 hour of drilling two 1/2" holes to go over the mounting bolts and some grinding. Fan nut popped loose like a charm. Got the job done in about two hours as the thermostat replacement was simple, removing stuff in the way took the time. The pictures and procedure at Pelican made it a diy project saving $$$ on labor and buying the part from them it was a perfect fit. Thx
January 19, 2010
  Followup from the Pelican Staff: Thanks for the additional Info. We appreciate it. - Nick at Pelican Parts  
BigC Comments: Hi there, I'm looking at replacing the thermostat in my e46 32 shortly. Someone has said this can be done without draining the coolant first as mine was flushed a few months ago. How much coolant will spill out of the thermostat housing if it's not drained? Obviously going to top it up and bleed it afterward.
Many Thanks
January 7, 2010
  Followup from the Pelican Staff: You will lose whatever is in the head and upper hoses. Maybe hal a gallon. - Nick at Pelican Parts  
HUGOCOL Comments: Wayne, I also forgot to ask you if it is safe to remove the oxygen sensor that is blocking the engine block draining plug.
I wanted to take the coolant that is in the engine compartment but realized that this sensor was in the middle not sure why BMW fabricated this cars like that. For some reason my car has this plug right next to one oxygen sensor. I know that this part is a bit expensive and do not want to damage it.

Thanks,

HUGO
December 21, 2009
  Followup from the Pelican Staff: Yes, if you need to remove it to access the drain plug, go for it. Just be careful not to damage the sensor during the procedure. - Nick at Pelican Parts  
HUGOCOL Comments: Thanks for replying so quickly Wayne. Your answer leads me to another question. This Vernet thermostat does not have an arrow to locate the part appropriately. I assume that the small indented dot is the reference point. Should this mark face up? The Thermostat installed on my car has an arrow facing down. I am not sure if the location really matters.
Thank you very much for your help. And thanks for sending me all my parts on time. Your site is the best on-line store I have found for BMW parts.
Thanks,
HUGO
December 21, 2009
  Followup from the Pelican Staff: If the metal casting is similar to the factory thermostat, put it int he same way the old one came out. Otherwise it shouldn't matter, that is if there is no bleed hole. - Nick at Pelican Parts  
HUGOCOL Comments: Hi Wayne,
I recently bought your Vernet thermostat 92 degres for a E36 328i 1997and looks a little different than the one that is installed in my car. The top portion has a thin metal kind of brace not sure what the name is....I just wanted to ask you if there are different shapes and would not affect the functionality. I do not want to install everything and then have to take everything off because of the thermostat. I appreciate if you can provide more information or confirm that the part I bought through your site really works OK!!

Thanks in advance,

HUGO PLAZAS
December 19, 2009
  Followup from the Pelican Staff: Hi there Hugo. I pulled up your order and then cross-checked it against the factory documentation we have here. The thermostat you ordered was 11-53-7-511-083-M164 and should fit all 328i cars with no problem. Throughout the years, it's common for parts to be redesigned, and sometimes they don't look *exactly* like the ones that were originally shipped with the car. In almost all the cases, the changes are a design improvement, most likely to address some flaw or defect that has been discovered since the car originally shipped off of the line. Hope this helps. - Wayne at Pelican Parts  
kourosh Comments: I have a 1999 E36 M3 . every time the weather gets cold check engine light comes one . I toke it to the shop they checked it with auto scanner .
Said fault code P0125
Definition:
Coolant temp is always low
Explanation:
The power train control module verifies that the engine is at a proper operating temperature.
Probable cause:
1- check coolant level
2- thermostat defective
3- ECT engine coolant temperature sensor defective.
Coolant level is good , so they told me I need to change thermostat and ECT sensor ..
Mr. Wayne PLEASE help me to solve this problem ?????? THANK U
kourosh_foroughi@sbcglobal.net
December 16, 2009
  Followup from the Pelican Staff: Hi there. I would probably agree with them that the thermostat may need replacement. It may be stuck open, which means that the car has trouble warming up full, and is "leaking" fluid into the radiator, past the thermostat. Not a terribly huge problem, but annoying nonetheless. - Wayne at Pelican Parts  
kb Comments: Hey Wayne, right now I'm almost through this job and my engine is looking like Fig 2 of this DIY. How did you get the block all nice and clean like Figure 8??? what type of cleaning solvents? You use a metal brush? This stuff wont come off!!
December 14, 2009
  Followup from the Pelican Staff: I cheated, sort of. The head was cracked, so it came off and went to the machine shop where they cleaned it and blasted it before they welded it. So, it does look a little artificially clean there. I would try a wire brush on a drill like I used on the top of the block. - Wayne at Pelican Parts  
Bob Comments: 87 325ci, with 130k miles, Is it common for the thermostate to stick open? My car never seems to warm up and the motor stays pretty cool unless i go on a long trip. Should i suspect the thermostate or is there another common cause for this? Thanks in advance! Bob
December 5, 2009
  Followup from the Pelican Staff: Yup, that sounds like it could be a stuck thermostat. You can check by feeling your radiator hoses when you first run the car. If they are hot / warm within a few minutes of driving, then the t-stat is probably stuck open. Better stuck open than closed! - Wayne at Pelican Parts  
rrrrobby Comments: Is there a specific sealant that is to be used for the thermostat housing or can some general-purpose silicone from Home Depot / Lowe's be used?
November 2, 2009
  Followup from the Pelican Staff: Don't use the stuff from HD or Lowes, but instead get some good Permatex or similar engine sealant from your local auto parts store, and you should be fine. - Wayne at Pelican Parts  
lin Comments: yes hi we have a 318ti b.m.w. 1995 model our engine has twin cams the thermostat housing is a aluminum one and we been told they dont make them well sorry but its true anyway there are no pics how to remove the thermostat for our motor it has a sensor thingy in front of the thermostat housing can you help as we are not sure what to do in case we disturb that sensor we think it is in front please please help with pic if possible
October 22, 2009
  Followup from the Pelican Staff: if the sensor is in the way, it has to come out. We do not have your style here in the US, so I cannot give more specific advice. - Nick at Pelican Parts  
Davef Comments: repie to pelican staff. Thanks for you response guys but i have bleed the system about 30 times since new pump and rad...
replie to ZA, Thanks ZA but have now tryed this and no change.
P.S. Just noticed that when temp starts to rise electric radiator fan comes on but only for a short time not untill temp is back to normal, could this be the problem? running out of ideas now had this problem for a couple of months. Dave
October 18, 2009
  Followup from the Pelican Staff: If you have to keep bleeding the system and it is running hot, this could indicate another issue. I would pressure test the cooling system. If the system does not hold pressure and there are no external leaks, you may have a faulty head gasket. - Nick at Pelican Parts  
ZA Comments: DaveF
I used to have a similar problem. I found it to be electrical. Disconnect the battery for a while and then reconnect. It solved my problem , hope it solves yours.
October 16, 2009
  Followup from the Pelican Staff:
Thanks for the input on this one. We appreciate the help. - Nick at Pelican Parts
 
Davef Comments: Hi,
I have a 318ise 1999 E46, it has a overheating problem and losing coolant so i replaced the radiator with one off a 2004 model,replaced the water pump and found bits of plastic in engine from a earlier pump, and replaced water rail which is under the inlet manifold,someone had removed the thermostat from housing so left it as is,now after sitting in traffic for more than 4/5 mins the temp creeps up into the red until i put heater on full and it returns to normal in minuets.
Please help me sort this problem Thanks Dave
October 15, 2009
  Followup from the Pelican Staff: Put the heater on full and then rebleed the system - I'm betting that you have a big air bubble in there. I've had to bleed my cars 3-4 times after doing water cooling system changes. - Wayne at Pelican Parts  
mshmbo Comments: Hi,
I have 320i 89 and I tried to pull off the Thermostat bu it hits the injectors feeding tube at its side from beneath
Please help me solve this
Many Thanks
July 2, 2009
  Followup from the Pelican Staff: I'm not sure what you mean, send me an email at wayne@pelicanparts.com with a photo...- Wayne at Pelican Parts  

Got more questions?  Join us in our BMW Technical Forum Message Board, and ask a question to one of our many automotive experts.
  Search our site:    

View Cart & CheckOut | Project List | Order Status |  Help    

 

[Home] [Customer Service] [Shopping Cart] [Privacy Statement]
 [Contact Us] [About Us] [Shipping] [Map to our Location]

Copyright © Pelican Parts Inc.