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 > Technical Articles: / BMW E36 3-Series (1992-1999) >
Time to Rebuild? Part 1

Pelican Technical Article:

Time to Rebuild? Part 1


2 hours2 hrs






Your brain and investigative skills

Applicable Models:

BMW E30 3-Series (1984-93)
BMW E36 3-Series (1992-99)
BMW Z3 (1996-02)

Parts Required:

101 Performance Projects For Your BMW 3 Series 1982-2000

Performance Gain:

Diagnosing and fixing lesser issues with your BMW engine that will help you delay an engine rebuild

Complementary Modification:

Have your engine rebuilt
101 Performance Projects for Your BMW 3 Series

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.

When to Rebuild?

Indeed, this is a very common question, and one that is often not easily answered. Obviously, if there is the end of a rod sticking out of your engine case, then chances are, itÂÂ's time for a rebuild. However, with more subtle noises, broken pieces, and poor performance, the rebuild decision may not be crystal clear. In this section, I will provide you with some questions to ask yourself and some answers to common myths, in the attempt to correctly determine whether your engine needs to be rebuilt.

As with any serious medical condition, itÂÂ's always a wise idea to get a second opinion. The same is true with BMW engine rebuilds. Very often, I have heard of unscrupulous (or even over-meticulous) mechanics who have recommended, or even insisted on a rebuild, when not all of the signs pointed in that direction. Keep in mind that no matter how well-intentioned your mechanic may be, he may have a vested financial interest in seeing you rebuild your BMW engine. Of course, not knowing that youÂÂ're armed with this book and prepared to do it yourself, he might recommend a full rebuild. Rebuilding engines is a good business, and will guarantee about 40 hours of labor for complete job.

My recommendation is that you take your car to a second, independent mechanic, and pay to have the car evaluated. Have him perform a leak-down test on the engine (see later in this chapter), and let him know up-front that you have a master mechanic friend waiting in the wings to rebuild the engine for you. The goal is to try to get an independent, unbiased expert view of the condition of your engine. Many of the problems with BMW engines can be somewhat subtle, and difficult for a novice to detect and decipher. IÂÂ'll give you some hints, tips, procedures, and clues to help you in the following sections, but getting at least two expert opinions is always a wise idea.

High Mileage Engines

Each derivative of an BMW engine has itÂÂ's own quirks and problems. Some engines are known for their longevity, and some are decidedly not. Just because your engine has a lot of miles on it, doesnÂÂ't mean that itÂÂ's automatically time for a rebuild. With proper care and maintenance, certain engines can easily last 250,000 miles or more. Of course, some years have had better track records than others, but the basic rules apply: if the engine was well cared for, and not abused, then it should last a long time, and gradually wear out. In general, the rule of thumb is that high-mileage is not a good yardstick measurement of engine condition. The methods by which the car was operated and maintained during its life affect the condition of the engine much more than the mileage total.

High mileage engines often show signs of their age in compression and leak-down tests, described later in this section. As the engines age and mileage increase, the small tolerances within the engine slowly become larger. While this usually doesnÂÂ't result in a catastrophic breakdown, high-mileage engines will gradually see their performance degrade as the mileage increases. Such an engine may be referred to as 'tired'.

Stock engines almost always last longer than modified engines. Higher compression ratios, aftermarket turbos, or superchargers will almost always place added stress on engines and make them wear out or fail quicker. Engines driven constantly on the track may especially show signs of wear. Race engines have such a typically short lifespan that their usage is usually tallied in hours run, rather than miles traveled.

Failed Smog Tests

Out here in sunny California, we have one of the most strictest emissions tests in the world. Cars are held up to high standards that seem to get higher each year. Recently the California Air Resource Board (CARB) instituted a dynometer test where the wheels of the car are placed on a roller, and tested for emissions at a specific speed. In addition, the tests monitor hydrocarbons, carbon monoxide, and nitrogen oxides (NOx). These tests are designed to monitor the emissions for engine conditions that might produce smog. Unfortunately, as the tests get tougher and tougher to pass, more engines tend to fail. In some cases, the tests hold the cars to emissions standards that they were never designed to meet.

Just because your car fails the smog test, doesnÂÂ't necessarily mean that its engine needs to be rebuilt. In fact, a recently rebuilt engine will most certainly fail the test if it hasnÂÂ't been fully run-in yet. The best thing that you can do to get your car to pass a smog test is to make sure that it is running perfectly. Most of the time a non-passing car simply has its timing set incorrectly, or has a fuel injection problem. You must make sure that all of your fuel injection and ignition components are working 100% properly before you can assume that the engine mechanicals may be suspect. A compression or leak-down test should be able to let you know if your failure to pass smog is caused by internal engine wear.

Poor Performance and Poor Gas Mileage

When rings and valve guides begin to wear, the result is an increase in burnt oil inside the engine. Also seen is a decrease in compression. Both will have a negative impact on the power generated by your engine. The burnt oil is a contaminant in the combustion chamber and will interfere with the combustion process. The loss of compression will reduce your compression ratio, and limit the power output of the engine. Both will result in poor performance and poor fuel economy.

However, there are plenty of other factors that can affect fuel economy and power. Most notably, the fuel injection system needs to be maintained in top shape in order to achieve the most power out of your system. Make sure that you have eliminated both the fuel system and ignition system as a potential source of problems before you decide you need a rebuild. Also try to isolate and fix other obscure problems that you might not think of. Improper suspension alignment can seriously reduce power, as can improper tire inflations. Brake problems (especially with the emergency hand brake) can drag on the wheels and create some pretty significant drag. My upcoming book in this series, ÂÂ"101 Projects for Your BMW 3-SeriesÂÂ" will have more information on fixing these problems.

Strange Engine Noises

Water-cooled engines are designed to expand and contract as they heat and cool. As such, it is very difficult to diagnose strange engine noises that occur when the engine is cold. It is not uncommon for the engine to make some unusual tapping or knocking noises when started stone cold. ItÂÂ's the strange noises that are made when the engine is warm and running that are the ones to watch out for. All engine also tend to get noisier as they age, and clearances between parts inside the engine become larger.

Engine noises are indeed difficult to hear at times. What may be a loud noise from one area of the engine, may in fact be inaudible from another angle. Sometimes sitting inside the car, you will hear more of the lower-pitched noises, as the higher-pitched ones are filtered out by the carsÂÂ's insulation. Closing your eyes when listening to the engine helps to eliminate potential distractions, and allows you to concentrate on isolating the engine noises from one another. An automotive stethoscope is a useful tool for listening closely to the engine. This tool works best when placed against a solid piece of the engine. Local sounds from troubled components can be heard better through the stethoscope because it helps to isolate outside noise. A long wooden dowel is a good alternative to the stethoscope, but be careful not to stick it in your ear, as intermittent engine vibrations can sometimes knock it into the inside of your ear. A piece of rubber vacuum hose will work as well.

There are four basic types of noises that can come from the typical engine. Intermittent noises occur at irregular intervals and seem to have no reasonable pattern to them. An example would be something rattling around inside one of the valve covers. There are noises that emanate with the crankshaft speed, and occur once every revolution. Then there are valve-train noises which come and go once every two revolutions (on a four-stroke engine, the valve train operates at half the speed of the crankshaft). Such a noise would include the rockers and valve noise. This is probably the most common noise heard, and the fix may be to simply adjust the valves.

A common noise to hear is a loud squeaky noise from inside the engine while running. Such a noise can often be attributed to worn alternator bearings or a bad fan belt. Take the fan belt off, and run the engine for no more than 10-15 seconds and see if the noise disappears. If it does, you know the problem is with your alternator or belt system.

Another common noise is piston slap. This is the sound that the piston makes on its power stroke when clearances between the piston and the cylinder are somewhat excessive. ItÂÂ's a dull-thud clunk that can be heard every two rotations of the crankshaft. Piston slap is most commonly heard when the engine is warming up, before the piston to bore clearances have decreased due to the pistons expanding.

There are a whole host of noises associated with problems such as rod knock, noisy valves, broken rings, chain tensioner failure, detonation, and broken or pulled head studs. Unfortunately, I have discovered that itÂÂ's nearly impossible to accurately describe these noises in writing so that someone can diagnose them. The best suggestion would be to take your car to your mechanic and have him listen to the engine. An engine can be loud and noisy, and if you havenÂÂ't listened to a whole lot of them, your imagination can get the best of you. Of course, listening to other finely tuned engines in cars owned by your friends will help you with an idea of what a normal engine should be sounding like.

Oil Consumption & Smoking

As your engine ages, it will consume more oil. When the engine is brand new, all of the clearances inside the engine are easily filled with a thin film of oil. As the surfaces wear, the clearances enlarge, and oil begins to slip by them. This oil is then burned in the combustion chamber, as it seeps past the valve guides and piston rings. The wider the clearances, the more oil will be burned away. Also, some oils have different viscosities, and tend to burn at a higher rate than others. In general, thinner, lighter-weight oils have a tendency to flow more easily past worn parts in the engine. Use of a heavier weight oil in a tired engine may help to slightly reduce oil consumption.

In addition, excess clearances mean that the oil films that float the crankshaft bearings require more oil to work properly. Looser gap clearances between bearings means that oil flows more easily around the bearing journals. The result is that more oil is required to do the same task, and there is a corresponding drop in oil pressure and an increase in wear. This small drop in oil pressure can sometimes be seen if careful observance to oil pressure readings are taken over the life of the engine. In general, an increase in oil consumption, coupled with a decrease in oil pressure, is a sure-fire sign that the clearances in the engine have increased, and the engine needs to be rebuilt. In addition, the presence of oil in the combustion chamber may have an adverse affect on the combustion process. Oil tends to lower the effective octane rating of the fuel mixture, thus making the engine a bit more prone to harmful detonation.

So how much oil should your engine be consuming? One quart per 1000 miles is about the standard amount for most engines, as quoted by BMW. Newly rebuilt engines with about 5,000 miles on them will usually burn this amount. If your engine is consuming significantly more oil than this, you have a problem. Consumption of two quarts per 1000 miles is certainly cause for concern. Check your owner's manual for information about how much oil your particular model and year car should use.

There are two places that the oil can be lost, either past the piston rings, or the valve guides. If the car is excessively smoking, then there is significant oil being burned in the combustion chamber. Engines expand significantly when they are run. ItÂÂ's not uncommon for some engines to expand more than 1/8 of an inch side-to-side when heated from stone cold to operating temperature. This means that certain clearances that are designed to be optimum at operating temperature are sometimes not ideal when the engine is cold. Oil seepage when the engine is cold is considered normal. For example, just about every older engine smokes when itÂÂ's started, primarily because some oil has seeped into the combustion chamber when the engine was cold. This smoking is not necessarily a sign that the engine needs to be rebuilt. A more accurate test would be to check for significant smoke when the car is completely warmed up.

What smoke should you look for? White smoke is typically caused by condensation in the engine, and is generally harmless when seen on an air cooled engine. Black smoke means that there is a lot of unburned fuel in the combustion chamber that may be a sign that the car is running too rich. In general, blue, sooty smoke is burning oil. If your engine puts out a big puff of bluish smoke when pulling away from a stoplight, itÂÂ's probably a sign that the rings are significantly worn.

Worn rings also produce what is known as blow-by. Just as oil can enter into the combustion chamber, exhaust gases can also be blown into the crankcase when the piston fires. Such blow-by, as it is called, often comes out of the crankcase through the crankcase breather hose on the top front of the engine. This hose connects to the oil tank, and the exhaust gases are recirculated back into the engine through the filler neck on the oil tank. On some cars, blow-by is typically funneled back into the air filter through the positive crankcase ventilation valve (PCV).

Worn valve guides can also contribute to oil loss, although typically less than worn rings. In the mid-1970s, manufacturers sometimes experimented with new types of valve guides that did not last long at all. As a result, many of the engines had to have their guides replaced at about 60,000 miles. Most of these engines have had this repair done, however, if you find that your engine has not, then you can expect that your guides will be well worn. Worn guides not only leak compression, but also can cause the heads of valves to overheat and break off. This is because close valve guide clearances are necessary for proper cooling of the valve. It should be noted that puffs of smoke on deceleration are usually a sign of worn guides and valve seals.

In addition to the oil burned naturally by the engine, your engine can also lose a lot of oil due to leaks. Many oil leaks drip onto the exhaust pipes and are burned off by the high heat. As such, sometimes itÂÂ's very difficult to gauge exactly how much oil is being burned by the engine, and how much is actually being lost to oil leaks.

Air-cooled engines in particular, are infamous for oil leaks. Whether itÂÂ's a Porsche 911 engine or a Volkswagen engine, air-cooled owners will fondly describe that burning oil smell that is characteristic of these cars. To be fair, the air-cooled cars must get their passenger compartment heat from heat exchangers that wrap around the exhaust pipes. If there is an oil leak onto these pipes, then the smell of burning oil will waft up into the passenger compartment. This is the reason why many air-cooled owners diligently try to chase down and repair oil leaks in their engines.

Your engine can leak oil from one of many different places. Fortunately, many of these oil leaks can be repaired without tearing down and rebuilding the engine. See the upcoming book, ÂÂ" 101 Projects for Your BMW 3-SeriesÂÂ" for details on all of the common leaks that can be easily fixed without engine disassembly. If your main goal of rebuilding the engine is to fix some of these major oil leaks, I suggest that you read that section first.

There are a few major leaks that cannot be fixed without major engine work. Crankcase parting line leaks require disassembly, as do leaks between the heads and the cam towers or engine cases. Many times a leak will appear to be coming from one of these places when in fact it is leaking from a different point that is significantly easier to fix. Wash the underside of the car and track down all of the easy oil leaks before you decide that itÂÂ's time for a rebuild.

Reading Spark Plugs

The spark plug is really the best way to visually ÂÂ'seeÂÂ' what is going on inside your combustion chamber. You need to pull out all of the spark plugs to perform a compression test, so you might as well take a close look at them while their out. If you need to purchase a compression test kit, please visit this link: 

While todayÂÂ's modern fuels make plug-reading much more difficult, you can still glean a lot of information from looking at them. A good, well balanced engine will produce a plug that is light brown in color, and dry. If the engine is running too rich, the plug will often be coated with a lot of extra carbon. Keep in mind that the rest of your combustion chamber probably looks the same. An engine running too lean will have a powdery white coating on it, and the outer porcelain ring may have a burned appearance.

When reading spark plugs, pay close attention to the white porcelain ring around the plug. This white area will give you an excellent background to inspect the color of the plug, and to help determine how your combustion chamber looks inside.

If the plug is wet with oil, then that indicates that there is significant leakage into the combustion chamber past either the valve guides or the piston rings. This is generally a bad sign, and an indicator that your compression test may not yield good results.

Compression Tests

One of the most common tests that can be performed on a engine is the standard compression test. This particular test measures the amount of pressure that is built up inside the combustion chamber when the engine is turned over. The typical compression tester is a pressure gauge that is attached via a short hose to a plug that is screwed into the spark plug hole. As the engine turns over, the compression gauge will read the maximum pressure exerted within the combustion chamber. The overall value is one method of testing your engine to determine the condition of the rings or valves.

Your engine needs to be setup before you can start the compression test. With the car cold, loosen the spark plugs with a spark plug socket and extension. Then tighten them up very lightly. You want to test the engine when itÂÂ's warm, yet if the spark plugs are very tight in the heads, you can damage the threads in the heads by removing them when the engine is hot. Loosening them up a bit when the engine is cold will minimize any damage you could possibly do to the threads in the heads. Although you might think that itÂÂ's good practice to use anti-seize compound on the plug threads, one manufacturer, Porsche, specifically recommends against this. The anti-seize compound seems to interfere with the proper grounding of the plugs. Also, temporarily remove any heater hoses that might get in the way of removing the spark plugs.

Warm the car up to operating temperature and then turn it off. Wait about 5 minutes or so, as head temperatures tend to spike right after you turn the engine off. At this point, the engine fan has stopped, and the heat tends to build up with no place to dissipate to. Removing the spark plugs right after turning off the engine can cause the threads in the aluminum to gall. After about five minutes, remove the spark plugs from their holes. If youÂÂ're working on an early car, then simply disconnect the power line (+) from the coil. If youÂÂ're testing a car with the Motronic Engine Management System, then remove the small square DME relay that powers the system. Doing this will disable the carÂÂ's ignition system, and prevent the spark plug wires from firing. ItÂÂ's also a wise idea to remove the fuel pump relay at this time, if your car has one. You are going to be cranking the engine over several times, and you donÂÂ't want raw fuel to be dumped into the system.

Having a helper around is useful, as you can watch the gauge while he or she cranks the engine. I recommend that you attach a battery charger to your battery to avoid running it down. DonÂÂ't fire it up at 50 Amp, but instead leave it on about 10 amps, which should help it recover when itÂÂ's not cranking.

With the engine warm, install the compression tester into the spark plug hole. A bit of patience and skill are required in order to properly manipulate and screw in the compression tester so that you donÂÂ't cross thread and damage the threads in the cylinder heads. With the compression tester installed, crank the engine over 12-16 times. Make sure that you place your foot all the way down on the throttle. This will allow maximum air flow into the engine, otherwise your compression readings will be off. The engine should make six to eight full complete compression strokes (12-16 turns of the crankshaft). You can tell when the engine is on a compression stroke because the compression gauge will jump and show an increase when the cylinder is compressed. Carefully watch how the compression tester gauge increases, and record the maximum value when you have completed the last compression stroke. The gauge will jump at first, and then increase slowly until cranking the engine over more and more has no additional effect on the reading. Remove the compression tester and repeat for each of the other cylinders.

So what to do with the results? In general, compression tests are limited in what they can tell you. It is important to remember that different compression testers may give different readings as well. Cranking the engine faster (with a stronger battery or high powered starter) may also skew readings. The most useful piece of information that you can glean from them is how each cylinder compares to the others. All of the cylinders should give readings that are very close to each other. This would generally indicate an engine in good health. A good rule of thumb is that each cylinder should read a minimum of 85% of value of the highest cylinder. So, if the highest reading is 150 psi, then the minimum acceptable reading would be about 128 psi.

It is important to note that this would be an acceptable figure, but not necessarily ideal. In all practicality, all of the cylinders should be very close to each other (within about 5-10 psi). On a newly assembled and run-in motor, compression numbers are usually within this range. As the engine ages and certain parts wear faster than others, one or more cylinders may experience a bit more wear than the others. This will definitely show up in the compression tests. Needless to say, if you have all of your cylinders in the 150 psi range, and one cylinder is down around 120 psi, that should give you cause for concern. The important thing is to remember is that you want to gather consistent readings across all of the cylinders, without focusing on the actual values. If a reading is significantly off, go back and test that cylinder again to make sure that the measurement was not caused by some sort of fluke, which is often the case.

So what causes variations in compression tests, and why canÂÂ't they be used as the final word on engine rebuilds? The problem is that there are several factors that effect the final pressure read by the tester. Engines running with very aggressive camshafts have a tendency to give low compression readings. This is because there is significant overlap between the intake and the exhaust stroke on the cam. During high-rpm operation of the engine, this overlap works to give the engine more power. However, when turning the engine at a low RPM, as with a compression test, the overlap causes some of the pressure in the combustion chamber to leak out before the valve is closed. An early 911S engine, for example (with its high-overlap cams ) has a tendency to give lower compression readings than the 911 CIS engines (1974-83), despite having a higher compression ratio. This is caused by the aggressive overlap of the camshaft.

Altitude and temperature also affect the compression readings. ManufacturerÂÂ's specifications are almost always given at a specific altitude (14.7 psi at sea level), and 59° Fahrenheit. Both temperature and barometric pressure change as you go up in altitude, so you will need to correct your measurements if you wish to compare it with a factory specification. The following chart provides conversion factors for correctly compensating for changes in altitude:

Compression Test Altitude Compensation Factors
Altitude   Factor
500   0.987
1500   0.960
2500   0.933
3500   0.907
4500   0.880
5500   0.853
6500   0.826
7500   0.800



A standard compression reading of about 150 psi at sea level in Los Angeles would measure significantly less in the surrounding mountains. For example, at an elevation of 6000 feet, the expected reading would be 150 psi X .8359 = 125 psi. The cylinders would be reading low if compared to sea level measurements, yet perfectly fine at this altitude.

Another factor that can alter compression test readings are incorrectly adjusted valves. If the valves are not opening or closing at the correct time, then one cylinder may read vastly different than another. Make sure that your valves are adjusted properly prior to performing the test. Along the same lines of thought, premature camshaft wear can also lead to variances in compression readings.

You can determine if the rings are causing low compression readings by squirting about a tablespoon of standard 10-30W engine oil into the cylinder. Crank the engine 2-3 times to spread the oil around inside the combustion chamber. Then retest the compression. If the readings shoot up significantly (45 psi or so), then the problem is most likely with the piston rings seating to the cylinders. Squirting the oil inside the combustion chamber in this manner allows the rings to temporarily seal quite a bit more than they would dry. If the compression readings do not change, then most likely culprit is a leaky valve.

Leak-Down Testing

Without a doubt, the most comprehensive test that you can perform on your engine is a leak down test. While somewhat similar to the compression test, it eliminates nearly all of the extraneous variables that may alter the final compression readings in a typical compression test. In simple terms, the leak-down test involves pressurizing the cylinder and measuring the amount of air that is leaked out past either the rings, the valves, or out a gap between the heads and the cylinder.

The leak-down test equipment uses an external air compressor to pressurize the cylinder. The engine is held stationary, and the test is not dependent upon outside variables like the cranking speed, altitude, temperature, or the camshaft overlap. In fact, the leak-down test can be performed on just about any engine, whether or not it is inside the car or not.

Unfortunately, the leak-down test equipment is somewhat specialized, requires an air compressor, and is not exactly inexpensive. Most local repair shops have a leak-down tester, but itÂÂ's not common to find one in your neighborÂÂ's garage. The good news is that most shops will be able to perform a leak-down test on your engine for a nominal fee. Most BMW engines doesnÂÂ't require any special leak-down adapters, so you should be able to take your BMW to any good foreign repair shop, and they should be able to do the test for you. Similar to the compression test leak-down test should give you information on the condition of the rings and valves, but from a slightly different perspective. The leak-down test can be performed on an engine that is not installed in the car. However, if the leak-down test is performed on an engine that isnÂÂ't warmed up, then the test may not give accurate results.

The leak-down test is performed by initially setting the engine to top-dead-center (TDC) on the compression stroke for the piston that you are checking. Make sure that itÂÂ's exactly at TDC, otherwise the engine will begin to turn over as soon as you pressurize the cylinder. You want to make sure that both the intake and exhaust valves are completely closed (as they should be at TDC) otherwise air will immediately leak out of the cylinder. To make sure that you are at TDC for cylinder number 1, remove the distributor cap, and rotate the engine clockwise until the rotor is lined up with the small notch.

When you are running the test, it is a wise idea to make sure that the crank doesnÂÂ't turn at all. Have an assistant hold the crank steady or place a flywheel lock on the engine if itÂÂ's out of the car. Connect the leakage tester to the engine in the same manner that you would with the compression tester. Pump up the cylinder and let the leakage tester measure the amount of air lost. The gauge on the tester should give readings in percentage numbers. A newly rebuilt engine should have leak-down percentages of around 3-5%. An engine in good running condition should show 10% or less. Numbers around 20% indicate some wear of the engine, but are still adequate for good engine operation. Leakage numbers of around 30% indicate that there are problems brewing, and that a rebuild may be necessary. Needless to say a large leakage amount like 90% indicates that there is a hole in the combustion chamber, and the engine is probably not firing on this cylinder at all. Rotate the engine crankshaft clockwise 180° when youÂÂ're done, and check the next cylinder. Repeat the process for each of the six cylinders.

Another good quality of the leak-down test is the ability to pinpoint the exact problem with the engine. When the cylinder is compressed with air, you can usually hear where the air is releasing from. Leakage past the intake valves can often be heard at the intake manifolds through the fuel injection. Exhaust valve leakage can sometimes be heard through the tailpipe. Leakage past the rings can sometimes be heard in the crankcase breather hoses. The most obvious leakage occurs when the cylinder heads have broken or pulled, and the air leaks directly out of the combustion chamber in-between the cylinder and the head.

While the leak-down test is probably the best indicator of engine condition, it shouldnÂÂ't be the final word in your evaluation. I have heard from many people about great running engines that for one reason or another do not test well on the leak-down tester. ItÂÂ's important to remember that the leak-down tester does not test the engine when itÂÂ's running ÂÂ- it only does a static evaluation. As with any air cooled motor, itÂÂ's operating characteristics vary widely. Use the leak-down test as one indicator and back it up with other tests and observances.

Carbon Deposits

I thought it important to mention some things about carbon deposits build up inside engines. Just about every single engine I have ever seen torn open has had a significant layer of carbon buildup on the pistons and the inside of the heads and valves. Particularly with todayÂÂ's ever changing formulations of gasoline, the additional carbon build up appears to be a problem in almost all air-cooled engines.

Carbon deposits will form naturally inside the combustion chamber as a natural by-product of the combustion process. Both engine oil and gasoline are hydrocarbons, so burning either of them incorrectly can result in a buildup of excess carbon deposits. These deposits are often caused by excessive oil burning in the combustion chamber, which is a sign that your engine needs a rebuild regardless. In addition, a rich mixture setting can also introduce more of the black soot that creates the carbon buildups in the engine. Short-trip driving and extended idling (not ideal running conditions for an engine) can also increase the buildup rate. While excess carbon deposits can be cleaned and removed without a complete overhaul, very often they are yet another sign that something else on the engine needs attention (like rings and guides).

Carbon deposits can cause the engineÂÂ's valves to become shrouded, and covered with carbon. In an opposite manner to porting and polishing the heads, the carbon buildup actually disrupts the flow of fuel mixture, and can restrict the airflow into the combustion chamber. Even if the engine has had a relatively short number of miles put on it since its last rebuild, you may discover that it has very low or zero compression in one of its cylinders. Often the reason for this is carbon deposits. When an engine is left idle for a long period of time, moisture has a habit of getting into the combustion chamber, and gets absorbed by the carbon deposits. This absorption results in the carbon becoming loose and flaking off. Carbon deposits that flake off have a bad habit of getting lodged in-between the exhaust valve and itÂÂ's seat. This creates a compression leak in the combustion chamber.

ItÂÂ's important not to drive the car for extended periods of time (hundreds of miles) if you think that a piece of carbon might be lodged in-between the exhaust valve and its seat. The reason for this is simple. The exhaust valve (unlike the intake valve) becomes very hot, and needs to cool by coming in contact with its valve seat. If the valve doesnÂÂ't seat properly, then it will be thermally isolated from its heat sink (the seat in the head). Prolonged driving in this condition will cause the valve to become burned, and will develop a typical pie-piece shaped notch in the valve. Valves damaged in this manner are basically destroyed, and will not seat properly even if the carbon is removed. In the worst-case scenario, the valve will become so hot that the head of the valve can break off. Having the head of a valve dance around the inside of your combustion chamber will usually destroy the piston and send chunks of metal circulating throughout your motor. Needless to say, this is not a good thing.

As mentioned previously, worn valve guides, or worn out rings allow excess oil into the combustion chamber that vastly increases carbon build up. Of course, the solution to this problem is a full rebuild, or at best a top-end valve job. In addition, how you drive your car can affect the build up of deposits. Short drives around town have a tendency to increase the level of carbon buildup. Slow-speed, short-trip driving has a tendency to not let the engine heat up to normal operating temperatures. Excess carbon deposits can often be ÂÂ'burned outÂÂ' by driving on the highway for about an hour or so. This should allow the combustion chamber to heat up enough to burn away the carbon deposits.

If your engine has been sitting for an extended period of time, you may want to try using a gasoline additive to your fuel. Berryman B-12 Chemtool and Techron both have good reputations for helping to dissolve and remove deposits. One of the best things to do is to take your 911 on an extended, spirited drive of at least an hour or more along the freeway. Try to vary your RPMs, but make sure that you keep them relatively high to help raise cylinder head temps. The cleaning process combined with the heated cylinder heads should be enough to clean out any excess deposits. When you return from your drive, run the compression or leak-down test again, and you may be surprised at the improvement in the numbers!

Next month, take a breath, we'll discuss the various costs involved with tackling a rebuild of your engine!

Comments and Suggestions:
duquey Comments: hi im currently rebuilding a m20b20 and im looking for ring gap sizes, any help would be great. std bores
October 17, 2017
  Followup from the Pelican Staff: For this model: 1990 BMW 325i (E30) L6-2494cc 2.5L SOHC (M20)

Ring End Gap
Row Note: First Compression 0.008-0.016 in
Second Compression 0.008-0.016 in
Oil 0.008-0.016 in
Ring Side Clearance First Compression 0.0008-0.0020 in
Second Compression 0.0008-0.0020 in
Oil 0.0008-0.0022 in
- Nick at Pelican Parts
fidel Comments: Hi,I have an 1997 328i bmw and i have a "crank but no start" problem. i was wondering if anyone might know what the problem might be and how i can fix it. please can someone help me with some suggestions. Thank you
April 16, 2017
  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 fuel pressure, volume, quality and engine compression. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.
- Nick at Pelican Parts
Noah Comments: Have a 1999 328i putting out hella smoke now after being ran hot !is car worth 800$ & could luqied glass help for quick temp fix
February 13, 2017
  Followup from the Pelican Staff: I am not familiar with liquid glass. The value f your car depends a lot on how it looks and was maintained... - Casey at Pelican Parts  
mulsky Comments: hi I have a 1988 bmw 325i that is getting oil into the inlet manifold and into the airbox. The engine had a full rebuild last year to solve this problem but its still there.
Its had new rings, valve stem oil seals etc but still seems to put oil in the inlet manifold especially after a motorway journey.
January 30, 2017
  Followup from the Pelican Staff: Check the crankcase breather for a faulty diaphragm. - Nick at Pelican Parts  
graeme2194 Comments: My 1997 bmw 318ti has 341,xxx miles and counting. I want to keep it as long as i can. Ive been thinking of getting an Oil Analysis. It is supposed to tell me how much life is left. Any thoughts?
November 24, 2016
  Followup from the Pelican Staff: They can be helpful to catch a wear issue. For example the metal types they discover can alert you of oncoming issues. - Nick at Pelican Parts  
J.Cole Comments: If a leakdown is performed on a cold engine without any oil in it a pulled motor, since there is no oil pressure, what effect would this have on the VANOS controlling the pressure in each cylinder? Is there any possibility that the valves could assume a position that provides an improper pressure reading?
November 11, 2016
  Followup from the Pelican Staff: I've never run into that. To prevent that, remove the valve cover and set the camshafts at TDC using locking tools. - Nick at Pelican Parts  
Camo Comments: Howzit id like to know if i could do rings and bearing while block is still bolted on car its a E36 316i m40 motor
October 17, 2016
  Followup from the Pelican Staff: Yes it is possible. - Nick at Pelican Parts  
jaidfox Comments: hello,my e36 engine need to be rebuild as the car smoke blue smoke and there is an oil on the engine and there is oil on the sparks also the engine is losing much power,so i think it need to be rebuild my question is do you sell rebuild kit??
bmw e36 320i 1997 m52 engine ....
July 22, 2016
  Followup from the Pelican Staff: It will most likely be a combination of kits.

Give The Pelican Parts parts specialists a call at 1-888-280-7799. They can figure out what part or repair kit you need.
- Nick at Pelican Parts
E34 trouble Comments: I'm in the process of changing a cracked head with bent valves on my 1994 E34 525i with 188,000 miles but when hand cranking with the head off there is a noticeable noise when one of the piston reaches the top and at the bottom of each stroke, I'm certain it's the rings but does the noise mean they have broken? Because they do sound loose. Most probably due to a bad overheating epersode a few years back I'm guessing, and if I'm replacing all the rings is there anything else I might need to replace like bearings and stuff because if so then I may have to scrap the idea due to a lack of cash. Thanks.
May 9, 2016
  Followup from the Pelican Staff: I would assume they are damaged. Best bet is to remove them and inspect each piston ring set and ring land. - Nick at Pelican Parts  
rbail1 Comments: I have a 2000 540i with 178,000 miles. Did a compression test and bank 2 is all good with readings in 168-175 range. Bank 1 is all low 150s to 161. Car runs good and idles smooth w/ no overheating. If it were rings, I thought it to coincidental that they are all on bank 1. Head gasket, maybe? No oil in water, no water in oil. Could the timing be off just enough to affect compression without throwing a code or running rough? The numbers are not terrible just peculiar. I am doing a timing guide and valley pan job but am worried maybe this points to something terrible. I would hate to put all that money and time into it only to have to go back and do more to it. Any opinion is appreciated as I can't seem to find much info about this specific situation online. My local mechanic says maybe the cam is worn on that side? Possible? Probable?
April 19, 2016
  Followup from the Pelican Staff: If the entire bank is off, the timing may be off, causing low compression on one bank. Try setting the engine timing into locked position and seeing it if OK. - Nick at Pelican Parts  
Daniel Comments: Hi, i have a 318tds '97 engine with about 110k km's. Where i can get better cams and a lighter flywheel frontal olhar bmw's engines?

Thx, Daniel
March 26, 2016
  Followup from the Pelican Staff: Pelican Parts can put a good kit together for you. Give our parts specialists a call at 1-888-280-7799. They can figure out what part or repair kit you need.
- Nick at Pelican Parts
asif Comments: Hi there, I'm about to purchase a bmw e36 323i which has a cracked valve cover. The owner changed the camshaft or crankshaft sensor, then it just blew. Can you give us a reason why that may be and whether it could be repaired? Thank you
December 4, 2015
  Followup from the Pelican Staff: I would assume the breather system is restricted or the engine overheated.

Give our parts specialists a call at 1-888-280-7799. They can figure out what part or repair kit you need.
- Nick at Pelican Parts
UlrichE30 Comments: I have a 1991 E30 325i Convertible. On occasion on cold starts, a small plume of blue smoke comes from my exhaust and I don't see any smoke after that. Driving, there's no smoke. No smoke while idling. No smoke on acceleration or deceleration. I had a valve adjustment around 2000 miles ago and I'm just thinking it might be a small oil leak. I also am thinking I might need to run a thicker viscosity. I'm currently running 10w30 and factory recommends 20w50 in the summer if I remember correctly and 10w40 in the winter.

Any guidance?
August 21, 2015
  Followup from the Pelican Staff: Check if the valves look oily after sitting overnight. if so, the valve guide seals may be leaking. You can use a boroscope or remove the intake to inspect them. - Nick at Pelican Parts  
E21-driver Comments: Hi, very nice article about engine rebuild. I have an M10 engine with two liters and stock carb which I swapped into my E21 ex 1.6. The engine holds idle, but is running very rough and black dusty, especially in idle mode. Acceleration is rough, but high rpms seem to be ok.
I made a compression test, and all four cylinders showed exactly 101psi. Ok, it is low, but why are they so exactly the same ? A faulty engine would show problems in one or two cylinders. Head gasket and valve sealings are new, mechanical timing is also on right crank and camshaft markings. Carb is completely rebuild.
Could there be also a problem with ignition coil power or dizzy timing ? Or still mechanical problem ? Thanks in advance.
July 29, 2015
  Followup from the Pelican Staff: They are the same because timing is off, likely. - Nick at Pelican Parts  
Wilson Comments: I recently had my head gasket and transmission replaced and the mechanic returned it sounding like this:
It did not sound like this before I took it in, and a separate mechanic that specializes in BMWs said i have to rebuild the engine. What do you think?
May 27, 2015
  Followup from the Pelican Staff: Sounds like it had an oiling issue. I would check engine oil level and pressure. - Nick at Pelican Parts  
Glyn Comments: hi I have a BMW E46 320 d 0.5 reg it started banging under car when accelerating, I had new donut fitted at front of prop shaft and a new centre bearing mount and it still bangs bad under car when accelerating, have you any ideas. The clutch doesn,t slip or make a noise or judder at all, pulls away fine, drives ok till you put your foot down then it makes a really loud knocking under car.
April 22, 2015
  Followup from the Pelican Staff: Check the engine and transmission mounts. The driveline may be moving under a load.- Nick at Pelican Parts  
95BLK325i Comments: Thanks for all the great info. I drive a '95 325i with 234k, original clutch, exhaust, and burns no oil.
A If the car fails emissions, and it's got 234,000 on the original cat, might the cat be the only problem? B Two years ago, my car developed a regular, 4 beats/second tapping sound. Turned out it was only a loose spark plug my fault.
C I have a suspension question. Since my car is stock, alignment can only involve "toe." But, what worn suspension components will affect tire life/alignment, and would they be identified in a good alignment inspection, or should they be diagnosed before taking the car for alignment? A bad front lower control arm ruined two tires, and I'm about to buy a new set.
March 24, 2015
  Followup from the Pelican Staff: I usually suggest have the suspension checked before the alignment. This way the mechanic can identify frozen adjusters, loose parts or other issues. - Nick at Pelican Parts  
wally Comments: Hi guys
I'm wally my e30 320i stall whene I shift gears or if I want to go more thane 4500rpm can you help me pls
March 21, 2015
  Followup from the Pelican Staff: Does holding the accelerator open keep the engine running? When your engine stalls you’ll want to check the basics. Check spark, fuel injector pulse and fuel pressure, volume, quality and engine compression. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.
- Nick at Pelican Parts
iHorses Comments: Posting here in hopes that somebody would help resolve a problem. 2004 BMW 645Ci w/N62 & 89500 miles on it. About a year ago started to loose some oil about a quart every 4-5K miles, so I took it to a mechanic and it was determined that alternator bracket was leaking so front was rebuilt, including valve covers, etc - everything that typically goes into this kind of fix. At first, I though oil consumption stopped, but it just slowed to where I only needed a quart every 6-7K, basically right before the oil change. About a week ago, during a real cold for Texas evening, I got a "high emission" warning and check engine light on my way home from work. When I checked the code, it was related to secondary air pump. I cleared the code to see if it would come back, but the car run fine for about a month after that, so I kinda dismissed the issue.
Fast forward a month, and on again a colder night the light came back. This time I took it to a BMW dealer to do a thorough diagnostic, and they told me that both sidee exhaust ports and oil passages? are plugged with carbon, and need heads pulled and cleaned to the tune of some astronomical amount. So, I'm trying to determine what my course of action should be, as I like the car a lot, and want it fixed properly, but obviously do not want to spend a proposed $10K fix on a car that worth about that much right now. So to the questions:
1. Is it ok to drive a car as it is right now, seeing how the light was cleared again and hasn't come back over the last couple of weeks?
2. Is there a methods of cleaning burning off carbon deposits without taking apart the engine?
3. any other options of clearing our exhaust ports without taking the engine apart.
4. could it even be something else not carbon buildup, and I should get a 3rd opinion?
Thanks so much for your super-informative resource.
March 15, 2015
  Followup from the Pelican Staff: 1. Without the secondary air system working, your emissions are higher. That is is the only downside.

2. No. The ports are not reachable and very small. There is a special cleaning kit, the valves have to be removed to use it.

3. No.

4.Unlikely, but you never know. However, the carbon issue is very common.- Nick at Pelican Parts
EzEEE Comments: my 2004 745li has no compression on cylinders 1 through 4. It seems odd that all 4 cylinders on one side would have 0 and the other side is fine. There is a loud tapping noise from the engine. This test was done by a well known local indy shop. Could there be a blockage in the vacuum? Could excessive carbon on the piston rings cause rings to not expand? I'd rather not have to get a new engine. He said Vanos and eccentric shaft are fine. All codes are cleared. Thank you
March 5, 2015
  Followup from the Pelican Staff: I would assume the timing chain jumped or failed. - Nick at Pelican Parts  
gles Comments: HI guys, my 328 E36 M52 engine produces a blue smoke when i am driving and when i checked the throttle and intake..there was a lot of oil in it. What could be the problem with it? please help guys i am stuck
February 18, 2015
  Followup from the Pelican Staff: Sounds like an issue with the air / oil separator. Check if is has failed and is allowing oil into the intake manifold. - Nick at Pelican Parts  
Engapol Comments: Hi

My 2001 C320 had smoking issues at startup and after prolonged idling, a mechanic replaced the valve stem seals but it's still smoking just as badly. It's fine when driving though and he ruled out rings, PCV system and head gaskets.

He did mention that there was bad sludging when he pulled off the valve covers, could the oil flow be impeded somewhere to the point that it floods the top of the valves which causes them to leak?
February 5, 2015
  Followup from the Pelican Staff: If there was that much sludge, it could be an issue with the valve stem seals. i have seen them dry out from improper maintenance and cause smoking. - Nick at Pelican Parts  
Red Comments: Can you tell me what motors will fit in a 325i 2004 BMW?
January 3, 2015
  Followup from the Pelican Staff: An M54 6-cylinder. - Nick at Pelican Parts  
elijha Comments: Hello all first I want to thank you all at pelican for all your articles. I ended up spending over 2000$ of parts from pelican all went great car started up like a champ. But a few noises still checking the pulleys and all . It's a 1995 BMW 328i. Overvalued and complete.
1 st question what do I need to do to break it in well.
2 starting it has a dragging start like it's not timed well or something could that be it or something else?
Please a i need a good heads up on what to do from here on.
December 20, 2014
  Followup from the Pelican Staff: No break in period is required.

The starter may be worn, it will create a labored sound if so. - Nick at Pelican Parts
eric Comments: I have a 1990 e30 convertible. I'm the original owner and am now at 211,000 miles. Recently last 25,000 miles I've started to burn oil. Never used to add any between changes. Oil changed regularly since new. Drive spiritedly but not too harsh. Now burning 1 quart every 1250 miles seems pretty constant. I figure its the valve guide seals. Should I be concerned? Anything I can do without rebuild? Any idea how long the engine will go?

Thank you
December 17, 2014
  Followup from the Pelican Staff: That amount of consumption is considered normal by BMW. If you don't want to perform a major repair, keep and eye on oil level and keep it topped up. - Nick at Pelican Parts  
WAG Comments: Hello, I have a 2004 BMW 330i, with 98,000 miles. The engine makes a knocking/rattle sound upon start up, more pronounced during cold morning starts 30-40 degrees. The rattle is present for 30-50 seconds. After warm up, drive to work, let sit for 8 hours and re-start the engine doesn't knock/rattle. Sometime if you rev engine rev engine to 2500 RPM, let off the gas and then tap the accelerator once the RPMs fall off, the rattle can be heard. Fearing rod knock, but one would think rod knock would get worse as oil heats up and thins out. Could be piston slap, or wrist pin? as those expand with warm up and become quiet? Or valve train noise? The noise sounds like it's coming from the front of the engine, near the VANOS area of the valve cover. Clue; 18 months ago the car ran very low on oil, the indicator light/sensor was faulty and did not warn of low oil. I only became aware of low oil after the tick, tick, tick was heard. Shame on me for not tracking oil consumption. Your thoughts? I have a recording of the cold start up if you'd like to hear it. Help!
December 7, 2014
  Followup from the Pelican Staff: Could be a bad VANOS actuator. I have seen them cause rough starts and noise when cold. - Nick at Pelican Parts  
candaul Comments: Hello, I have a 2000 E39 M5 that rivals the Exxon Valdez in terms of oil waste. I use about a quart per 300 miles, sometimes more. The consumption has been going up with time. The car has 173K miles and oil is changed every 3K miles. The oil burning is very noticeable after a deceleration and then getting back on the throttle. As an example, if I drive uphill at full throttle for an extended period and check oil consumption at the top of the hill, no noticeable amount is used. However coming down the hill where decel is prevalent, I burn up to a quart. This behaviour is also evident on a freeway at night with the lights highlighting oil burning after a decel followed by accel. A simple acceleration run, does not show the same blue smoke. Oil used is a 20W50 Kendall high zinc type oil. But I've tried various types with no change in consumption. At 80K miles or so it was 1 quart per 1000 miles or so and becoming progressively worse. Is this a strong sign of usage due to valve guides or piston rings....or...?
There are no oil leaks from valve covers, no drips on the floor or on the underside of the car. I've looked at and swapped oil separators after cleaning. No significant amount of oil in the intake or throttle bodies.
Thank you.
December 3, 2014
  Followup from the Pelican Staff: Sounds like worn valve guides. First check that the crankcase breather valve isn't faulty. Both of those items will cause smoke under vacuum if faulty.- Nick at Pelican Parts  
Matt Comments: I have a 1995 BMW 325i.It has a blown head gasket I haven't done to much work on these cars and was told I have to watch what modifications I do provided that the block is good I want to get a scrap head install a bigger cam Andrews valves and springs wiseco high compression pistons and change the trans to a standard is this going to be possible
November 27, 2014
  Followup from the Pelican Staff: You can replace the pistons and cams. Just start with a good block and have a good machine shop do the work for you. Keep in mind, with any major engine modification, you are changing it from what BMW designed it for, so reliability can go out the window. - Nick at Pelican Parts  
Matt Comments: I have a 1995 BMW 325i.It has a blown head gasket I haven't done to much work on these cars and was told I have to watch what modifications I do provided that the block is good I want to get a scrap head install a bigger cam Andrews valves and springs wiseco high compression pistons and change the trans to a standard is this going to be possible
November 27, 2014
  Followup from the Pelican Staff: You can replace the pistons and cams. Just start with a good block and have a good machine shop do the work for you. Keep in mind, with any major engine modification, you are changing it from what BMW designed it for, so reliability can go out the window. - Nick at Pelican Parts  
JoeCoffey1 Comments: LOL. No, the shop that intitally did my starter dropped a plastic clip down my intake valve port causing it to stay open, vense the 0 compression. Took it to overseas service haus in frisco tx and they repaired it properly. I highly recommend Kyle and kevin @ Overseas. if you live in DFW have a BMW thats out of warranty and need repairs. I recommend these guys. Thanks
November 7, 2014
  Followup from the Pelican Staff: Crazy, glad you got it worked out. - Nick at Pelican Parts  
JoeCoffey1 Comments: I have a 2006 325i and went in for a starter replacement at an INDY shop here in dallas. After they relpaced the starter and fired it up it ran rough and i was told that my #3 cylinder was low compression. The car ran fine before the starter went out, is there any link to the cylinder being low?
November 4, 2014
  Followup from the Pelican Staff: No, I can't see the connection. Have they checked spark and fuel on the cylinder as well? - Nick at Pelican Parts  
jaidfox Comments: Hi there I have BMW E36 320i 1997 single vanos my problem is that I heard tick noise when I start my engine and sometimes when I drive the car for along time and when the weather is hot and I drive aggressive I hear strange noise while I'm driving the noise like tak tak tak or krrrrrrr and I think its valve noise I try many cleaners for engine and valve cleaners but its the same and there is power lose on my car and yesterday I revved my car and when the rpm on 7 a blue smoke came out from the oxzost but its not that mush and I check the oil everyday but its full so can you help me pls
September 21, 2014
  Followup from the Pelican Staff: I would check oil pressure to start. COuld be an oiling problem or worn lifters. - Nick at Pelican Parts  
mitch Comments: my car needs to be 're-timed' can you give me a clear indication on what I have to do, whether a rebuild or just a simple fix.
August 25, 2014
  Followup from the Pelican Staff: You didn't mention what vehicle you have. I would grab a repair manual. It will have the procedure, special tools and torque specs.

Give our parts specialists a call at 1-888-280-7799. - Nick at Pelican Parts
DJPhatu Comments: Thanks Nick. Yes I used a new part and there was no plug. But After a few more hours I think that we found the issue. The oil Separator Crank Case Valve or CCV has gone bad. This looks to be a huge job time wise, but not hard. Do you have any advice for this job??
July 30, 2014
  Followup from the Pelican Staff: We've got you covered. See this tech article: - Nick at Pelican Parts  
DJPhatu Comments: Hey there I have a 2004 325Ci European version. My car began making a sucking like vacuum noise from the Manifold control runner part 11617544806. There was a bad diaphragm inside. but now the new unit is a making a similar sound, right after install and we found that it is also sucking air from somewhere. Is this unit supposed to breathe there is a hole on the bottom of the unit, should there be a vacuum hose attached? I have attached a picture of the bottom hole on the unit
July 29, 2014
  Followup from the Pelican Staff: That hole in the bottom is a vent. It should be sealed. Did you use a new part? - Nick at Pelican Parts  
Pat C Comments: Thanks. The cat was replaced just before the Cal emissions tests. I assume that the ignition and fuel injection systems are prime suspects in this regard. Respecting predicting long term viability of the engine would you recommend a leak-down test? thanks, again.
July 24, 2014
  Followup from the Pelican Staff: I would start by isolating the misfiring cylinder. If needed, perform compression and leak down tests. - Nick at Pelican Parts  
Pat C Comments: I have a US model 94 E36 convert M50 engine w 210,000 mi that i have owned since new. It burns less than a quart of oil in 4,000 miles but just barely passed CA emissions test when I moved here last year due to high HC. It was just 1 to 3 ppm above the limit and finally dropped to 1 ppm below limit to pass on the third test. spark plugs were replaced-although they looked OK, O2 sensor was replaced. It has the original ignition parts and injectors. It also has lost some acceleration in the last couple of years. I want to restore the interior and keep it for another 100K miles but am afraid it won't pass the test next year. Any ideas? thanks.
July 22, 2014
  Followup from the Pelican Staff: HC is an indicator of engine misfire. I would have the catalyst tested, if other gases are on the high end, it may be worn cat. if the cat is in good shape, there must be a slight misfire. - Nick at Pelican Parts  
lu Comments: Hey I have a 1995 325I bmw with 296k miles and it over heats . my friend saw it and he said it had a big hole in the engine ? What could it be ? Iv tried putting a freeze plug and that didn't work, Every time I try to put water to the coolant fill it falls right through the engine, it spills it all out , if you can please help me out ill really appreciate it . Thanks
July 16, 2014
  Followup from the Pelican Staff: Maybe a hole in the block? I couldn't say without seeing the hole myself. - Nick at Pelican Parts  
Vinos Comments: Hi there, my 325i e30 has white sustances on the oil cap after starting the car in the morning then after few minutes of idling it disappears. Is that a sign of a blown cylinder gasket?
June 23, 2014
  Followup from the Pelican Staff: On the bottom side of the oil cap? Could be condensation. If the cooling system level is OK, it is probably normal condensation. Do you drive the vehicle a lot? If not, it is more likely to have condensation build up.- Nick at Pelican Parts  
georgie Comments: hi there I have a bmw 3series 228i 1999 sedan .... just fixed thermostst at the mechanics was running good for a day and now its overheating again there are no leaks at all me and a mate have checked ... wat else could it be ???
June 22, 2014
  Followup from the Pelican Staff: I would try to bleed the cooling system again. if it is not air bound, 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  
trefk13 Comments: Thanks for that - 1 last question as i am trying to reduce the oil consumption on my 1996 e36 328i it has done 193000 kms - what is the best mineral oil to use to potentially reduce the consumption - i have tried Penrite Fully synthetic 15w40, Ulx 100 Semi Syntheic 10w40, Valvoline 20w50 Mineral oil and all consume at the same rate - i have been told to go with a good quality thick mineral oil? Whats your thoughts
May 30, 2014
  Followup from the Pelican Staff: I am not familiar with a mineral oil that will reduce oil consumption. I opened a post in our forums. A Pelican community member may be able to answer your question.
- Nick at Pelican Parts
Trefk13 Comments: Hi - I have 1996 328i Convertible E36 M52 - it loses around about a quart of oil every 700 miles - lifters and vanos making very slight noise - mechanic says valves guides and seals are slightly worn but not too concerning. Everything else is perfect in this car and engine is very quiet - should i be looking to reconditioning my motor or just leave it for as long as possible - cheers mate
May 25, 2014
  Followup from the Pelican Staff: That amount of oil is fairly common. I would live with it for now, just keep an eye on the oil level so you don't run out. - Nick at Pelican Parts  
hjsna Comments: I have a 98 BMW M3 w/ 220k miles now. I've posted that it has a oil burning issue most likely due to worn piston rings. It was burning a quart about every 500 miles or so. I tried Lubro moly Motor Oil saver, it helped it a little. But still burns. I then tried Lucas Pure Synthetic Oil Stabilizer and it definitely cut it down big time. I bought 4 gallons of this stuff. A quart of this stuff is about $16, but you can buy a gallon for $33. It not only cut down the burning, it increased the compression and restored the power. It feels like I got a new car.
May 21, 2014
  Followup from the Pelican Staff: Thanks for the additional info. We appreciate it.
- Nick at Pelican Parts
cstacey Comments: It also had white smoke come out when it did this. It stopped then only had a little smoke while driving.Also for the 2005 BMW 745Li.
May 16, 2014
  Followup from the Pelican Staff: White smoke is coolant. I would check the coolant level, top it up if needed and pressure test the system. - Nick at Pelican Parts  
cstacey Comments: what does it mean when my 2005 745li 4.4 bmw service engine light comes on and says accelerates slow may cause catalytic damage
May 16, 2014
  Followup from the Pelican Staff: It means you have an engine misfire occurring that is happening enough to damage the catalytic converter. - Nick at Pelican Parts  
Deepak Sharma Comments: Hi,
The article is very good and knowledgeable. I have 2003 BMW 316i, It runs OK and smooth, no overheating but looks like loosing lot of oil. I get it checked thoroughly for oil leakage but there none external oil leakage. The Vehicle smoke is normal and has done only 50000 miles. Recently there have been CCV replacement, Oring changes and chain guide replacement but still loosing oil around a litre in 500 miles. Sometimes I see milky substance at the tip of dipstick, This is specially when oil is low.

I am not sure if the engine really need re-build . re-manufactured or problem with head gasket of something else. Mechanics are not able to give any clear answer.
Any help will be appreciated
April 5, 2014
  Followup from the Pelican Staff: The amount of oil you are using can be considered in the normal range. If it is burning it, it can be due to a worn engine. - Nick at Pelican Parts  
ethan Comments: Hello, I'm not sure what article to put this under but, my power steering fluid is leaking a little and if I accelerate fast a lot, like getting on and off the highway frequently, my coolant fan hits the fan shroud and gets locked up, breaking blades and destroying radiator. It has happened twice this year. The second time was covered by the dealership but I still feel like the problem isn't fixed. No problem as long as you accelerate slow.
April 1, 2014
  Followup from the Pelican Staff: Sounds like a bad motor mount. When the engine torques and moves, the fan makes contact. I would inspect them.

You'll have to check the power steering components for leaks.- Nick at Pelican Parts
Fred Comments: SO wait, there is a "time to rebuild" write up, but not a "rebuild" writeup? E36 Bentley manual doesnt have information rebuilds :
March 30, 2014
  Followup from the Pelican Staff: Correct on the article title. You will need advanced repair information, available from BMW. - Nick at Pelican Parts  
JJG825 Comments: Thanks for the write-ups!
I have a 1984 318i which has been blowing a pretty big plume of blue/gray smoke at start-up. My mechanic who I trust says I need to replace the valve seals. Compression test on engine showed the following: At normal temp: dry - 159,158, 165, 165 psi cyls 1-4; wet 165, 161, 170, 175 psi cyls 1-4. Do you think just seals and the valve work is enough the right call?
March 29, 2014
  Followup from the Pelican Staff: The compression numbers are not that helpful. I would need static, dynamic and first puff. Along with leak down readings. If you don't trust the mechanic, as for a second opinion. - Nick at Pelican Parts  
cheong Comments: engine had overhaul done.. each cylinder was balance at 125..fuel regulator was changed.. injector was being swap ard. plug cable changed.. still same prob
February 7, 2014
  Followup from the Pelican Staff: I would recheck the basic, as something has to be faulty. Also, the compression sounds low. Recheck static and dynamic compression. - Nick at Pelican Parts  
cheong Comments: it's sounds like a engine misfire from the exhaust... but onli happen when idle.. when driving everything is smooth and fuel consumption is good too
February 7, 2014
  Followup from the Pelican Staff: Then I would look for a misfire. Check spark, fuel and compression on each cylinder. - Nick at Pelican Parts  
cheong Comments: mine is a 318 m40 engine auto.. I have change my plugs, plug cable, engine and gearbox mounting, tps, icv and afm.. but my car is still vibrating.. overhaul is done recently and compression is now all balance.. tried swapping the injectors but problem still persists.. wat the cause?
February 6, 2014
  Followup from the Pelican Staff: You will have to determine if it is vibration or an engine misfire. Once you narrow it down, you can start to locate the source of the problem. - Nick at Pelican Parts  
Vinos Comments: I have a 1990 325i e30 BMW. I have changed the viscous fan, thermostat and the water bump but the car still overheats. I have noticed that my electric fan is not working, what could be causing that?
January 9, 2014
  Followup from the Pelican Staff: The fan could be faulty, a fuse could be blown or bad wiring.

I the vehicle overheats driving down the road, the aux fan is not the problem. I would check that the cooling system is bled properly and that the head gasket is not faulty. - Nick at Pelican Parts
stephen Comments: I have a 1998 BMW M3 that i purchased about a month ago. the car ran perfectly fine until the other day when i missed a shift and the rpm's went pretty high. IT then started misfiring on cylinder 5 i checked and it has spark and fuel. so that left compression. i checked the compression and all the cylinders were within spec except for cylinder 5 which had a dry test of 120 and a wet test of 150. i cant figure out what the problem is.
January 4, 2014
  Followup from the Pelican Staff: You will have to perform a cylinder leak test to see where the compression is going. Once you identify the source of the leak, you can plan a course of action.- Nick at Pelican Parts  
Dernstar Comments: Hi.
Here is another question. Could it be valve seats making it smoke? Someone was talking about using lead substitute? But I thought I would ask first... So would I be looking at a possibility of valve stem seals, or rings, or valve seats?
December 19, 2013
  Followup from the Pelican Staff: Worn valve guides do cause smoking. - Nick at Pelican Parts  
Dernstar Comments: Hi Again,

Would a WET COMPRESSION TEST tell me if it was the rings or not? Thanks.
December 17, 2013
  Followup from the Pelican Staff: The problem with a wet compression test is, it comes down to experience. In theory yes, but if you add too much oil, compression numbers will go up. - Nick at Pelican Parts  
Dernstar Comments: Can you remove the picture from my last comment? I didn't realize it has my License plate # on it, or blur the plate?
December 17, 2013
  Followup from the Pelican Staff: Done - Nick at Pelican Parts  
Dernstar Comments: One more thing the 1992 325i e36, still has plenty of power. But smokes, blue smoke, only under a heavy load. Like taking off fast at a stoplight... No smoke usually during idle.
December 12, 2013
  Followup from the Pelican Staff: Is the check engine light on? You could be burning a little oil, it shows up just under heavy loads. Keep an eye on your oil level. This will help to determine if it is bad enough to pursue. - Nick at Pelican Parts  
Dernstar Comments: Hi,

I have a 1992 325i that had a new head put on about 80,000 miles ago. It has some light blue smoke when put under heavy load. I noticed no one mentioned a Wet Compression Test. I thought a Leakdown Test would be done after a Wet Compression Test? What test will confirm if it the Valve Stem Seals or the Rings?
Also: for 'moises perez the 2ed' above, I had the same problem and it drove me crazy, it turned out to be the Crankshaft Position Sensor, car won't start without it. Cannot tell you how many mechanics tried to burn me, by trying to replace the fuel pump which is new,MAF, etc.
December 12, 2013
  Followup from the Pelican Staff: You can inspect the back of the valves for oil residue. If there is none, the rings might be faulty. - Nick at Pelican Parts  
vinos Comments: how many kilometres do I need to run a fully overhauled engine of a 325i e30
December 7, 2013
  Followup from the Pelican Staff: Are you talking about break-in mileage? Usually 1000 miles (1600 km) of normal driving without over-revving is recommended. But check with your rebuilder. They may have their own engine break-in schedule. - Nick at Pelican Parts  
moudine Comments: Hello , I have a 2000 e46 330ci and I noticed that if driven at high rpm for extended time it burns oil siginifically anf while running at low rpm it barely burns oil , when car at idle it doesnt smoke and when acelerating slowly to high rpm it also doesnt smoke but if u I press the accelaration suddenly full power I see puffs of black smoke coming out of the exhaust.
Could this be the crankcase or looks like something more serious ?
Thanks a lot
December 4, 2013
  Followup from the Pelican Staff: 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. Also, make sure the oil is fresh, not diluted by fuel.
- Nick at Pelican Parts
Drew Comments: I have a 91 318iS track car w/ 250+ miles. Still hauls ass but would like to do an engine swap to a 325 of anything with than 160 hp. What kind of $ and difficulty level are we looking at?
November 19, 2013
  Followup from the Pelican Staff: Now sure what the cost would be. You would have to mock up a parts list and then tally the estimated costs. You can go to a larger engine. You'll need to swap over many components and there will be experimenting. I haven't done it so I cannot offer any details. I opened a post in our forums. A Pelican community member may be able to answer your question.
- Nick at Pelican Parts
MORE Comments: Hi, I have a bmw e36 318tds compact 98'.I have a problem with my rev counter. After changing gear and putting my foot on the throttle, the rev counter revs from 1000 rpm to 3500 rpm, this happens from 2nd gear to 5th gear. Would this be the clutch slipping? PLEASE HELP.
November 11, 2013
  Followup from the Pelican Staff: Sounds like the clutch is slipping. I would have it inspected. A quick test, start engine, engage parking brake, put transmission into second gear, slowly let out clutch, vehicle should stall. be careful when performing this test as the vehicle will try to drive away or move. You want to let the clutch out very slowly. - Nick at Pelican Parts  
joey Comments: Hello, my 89 325is 2.5l had broken 5rocker arms off the intake shaft, I removed the head and noctice all valves bent, so by getting the cylinder head redone completely and timing belt change . Would this make my car be at its best again like a champ?
October 24, 2013
  Followup from the Pelican Staff: As long as the bottom end I is ok, if you fix the top end it should run like a champ.
- Nick at Pelican Parts
mpowa Comments: Having just completed a full strip and rebiuld taking 3mm off the block and 2 off the head due to a two pence piece being put in oil filla, now engine completed... I have a question
August 27, 2013
  Followup from the Pelican Staff: You should be able to do something, I would contact a couple of different manufactures of the kit and ask about them, check out what other people on the forum are using.
- Nick at Pelican Parts
noeinstein Comments: I've been all over the I-net hunting down crankshaft and connecting rod specs size and wear limits for a BMW E46, M52tu engine, with no luck. I might have to really go deep and hunt that info down in our local library. Unless you guys might have that info.. would greatly appreciate that. Thanks.
August 5, 2013
  Followup from the Pelican Staff: Not sure that info is available from BMW in their parts information. They do share bearing sizes, but not rod sizes.- Nick at Pelican Parts  
m321p Comments: I have a 98 M3' w/ 211,000 miles. It burns atleast a quart of oil every 1000 miles. What do you think of me trying Redline 10W60? I tried Redline 10W40 and 15W50, but it drinks it up.
August 2, 2013
  Followup from the Pelican Staff: I don't think oil will fix your problem. I would for the source of the oil loss or consumption. - Nick at Pelican Parts  
Puzzled Comments: Thanks Nick! I had that done before I noticed your response - both PCV valves were replaced and it is still blowing blue smoke on acceleration SOME TIMES so I am taking it back tomorrow to have the hoses checked.

I read somewhere in a BMW forum that the computer might also have to be reset by disconnecting the battery and that sometimes those orange gaskets are defective, so I ordered two more.

Can you think of anything else they should check?
July 22, 2013
  Followup from the Pelican Staff: The occasional smoke may be residual from the faulty breather valves. Takes a short time to clear it out. - Nick at Pelican Parts  
NOT A PINTO Comments: I have an x5 4.4i with 13lk. A week ago I noticed some bluish smoke on acceleration from the left exhaust and took it to the dealer who could not find the source. Three days ago the Check Engine light came on so I took it to an indy mechanic who got an emissions code and sent me to a muffler shop to have it tested: the cats and everything in the exhaust are working fine. The check engine light went off and my control check shows nothing. There was no smoke at all tonight when I was coming home and I was thinking maybe the problem was solved BUT as I rounded a corner the car purged the biggest, bluest, ugly cloud of smoke ever from my left exhaust. I called the dealer mad, so mad and now they think it might be the pressure regulating valve aka PCV aka CCV. This is so frustrating and embarrassing: a LOT of people stopped after the smoke cleared because they couldn't believe my luxury 70k vehicle was blowing smoke like an old Pinto!!! Can you PLEASE put up a DIY for those of us who don't have good dealer service in our areas? The DIY would be to RandR #13 in this OEM schematic. Thanks!
July 10, 2013
  Followup from the Pelican Staff: Try changing the PCV valve mounted on the valve covers towards the front. They are round and snap directly on the valve cover. The diaphragm usually breaks and they suck oil out of the engine - Nick at Pelican Parts  
abharoochi Comments: Hi,

I have an e36 316i '97 that currently has a M43B16 motor, the motor is completely shot and has to be rebuilt. I would like to upgrade to a M44B19. Would this be possible without having to change anything else? I would like to just drop in and drive or would there still be some work to be done?

I have done some research and i might have to either change my ecu or have it reprogrammed... any suggestions on where i can have this done??

If so what would i have to do and how will i go about it?

Your assistance will be appreciated
June 16, 2013
  Followup from the Pelican Staff: I would think installing the correct DME would be the minimum needed to make it work. Double check the wiring and sensors on each engine to be sure there are not more parts that have to be transfered.- Nick at Pelican Parts  
Alieu Comments: i have bmw 318tds water is mixing with oil inside the water reservoir. what might be the problem.
June 3, 2013
  Followup from the Pelican Staff: Oil and coolant intermix is most likely a faulty head gasket. - Nick at Pelican Parts  
top Comments: what does the signal slow cat. overheat coming out on dashboard mean? wht can one can one seeing that
March 12, 2013
  Followup from the Pelican Staff: This could refer to a temperature problem with your catalytic converter. Check your owners manual to determine the exact reason for the message. - Nick at Pelican Parts  
moises perez the 2ed Comments: I have a 96 318ti and everything under the hood was just put on last year wha and it cranks but wouldn't drive what can it be?
September 16, 2012
  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. Once you figure out what is missing, it will be easier to diagnose. - Nick at Pelican Parts  
nic Comments: 2005 330ci convertible never starts in the same amount of turn overs. sometimes it will only turn over half a time and engine will start and sometimes it will take 3 or 4 turn overs. But it always starts with one turn of the key. it is usually pretty erratic and never turns over the same amount of times even if you started just a few seconds or minute later. besides that it runs perfect and I've just never had a car do that before and I was just making sure this was normal for a bmw
May 12, 2012
  Followup from the Pelican Staff: This could be something as simple as battery voltage to something a bit harder to diagnose, a camshaft sensor. I would check what is missing when it cranks longer. Check spark, fuel injector pulse and pressure fuel, volume and quality. Once you figure out what is missing, it will be easier to diagnose. - Nick at Pelican Parts  
Dimsim Comments: I have a 93 e36 it has a bad knock in wich sounds like the bottom end it gets worse as I accelerate can u please help
February 9, 2012
  Followup from the Pelican Staff: Noises are hard to diagnose without hearing it. If it is in the bottom end, it could be a bad bearing or piston slap. It could also be another component resonating. - Nick at Pelican Parts  
togari Comments: I am replacing the timing chain on my 1998 BMW Z3 1.9 liter motor.

Prior to removing the lower timing chain cover, is it necessary to remove the air conditioner AC mount, the top rear bolt 13 mm hex of the mount is very difficult to access. I would like to avoid having to disconnect the AC compressor.
January 8, 2012
  Followup from the Pelican Staff: If you need to unbolt the compressor. Just lay it aside and leave the a/c lines attached. - Nick at Pelican Parts  
walt Comments: e36m31998runs strongbutstalls at idle
October 22, 2011
  Followup from the Pelican Staff: Check the idle control valve. - Nick at Pelican Parts  
cristof Comments: Hi there, i've got a 94 325is and intermittinly it is smoking excessively. it will smoke out a red light like a detroit diesel even. the compression seems to be on par with what is expected, and i dont suspect rings or valve guides be the problem. would you have any insite on the issue? maybe CCV is failing due to clogging etc.?
September 20, 2011
  Followup from the Pelican Staff:
White smoke is likely coolant. 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
Grand Comments: Hello, I have a 1987 325i convertible and I was wondering what other engine models would fit for it?
August 20, 2011
  Followup from the Pelican Staff: There were tow production engines:
I4, 1.6 - 2.5 L (66 - 178 kW)
I6, 2.0 - 3.3 L (92 - 145 kW)

You could also fit some other model engines in. There would be a need for experimenting. - Nick at Pelican Parts
BMW Lover Comments: Hello, I have 3 BMWs A 88 e30 with 395461 verifiable miles no motor work ever done just the maint. a 91 with 354987 have only done the maint and a 2000 323i with 407562 and have just done maint original clutch, expansion tank runs like a champ and they never use oil between service
June 16, 2011
  Followup from the Pelican Staff: Great group of cars, thanks for sharing. - Nick at Pelican Parts  
hein m5 Comments: hi.I live in south africa.i drive a bmw 2001 e39 many km,smileswill my engine is serviced as per bmw recomendations,parts and oils.i generally drive conservatively.there is a small leak at crack pulley and doesn,t use any oil when driven normaly.other thing.will the e46 6spd manual 330d rubber coupling between gearbox and propshaft fit on my m5. thanks.
June 16, 2011
  Followup from the Pelican Staff: You can get well over 200,000 miles if you take care of it. I have a friend who has one with 249,000 right now, still going! - Nick at Pelican Parts  
lenroy Comments: is it ok to file bmw piston rings?
April 27, 2011
  Followup from the Pelican Staff: To set gap? I would think they would come preset. - Nick at Pelican Parts  
blackbirdxx Comments: Please can someone explain the process to set the timing on the bmw x3 n47d20 engine, we set everything but at the end it goes out?? Why is this happening? Pls help!!
March 22, 2011
  Followup from the Pelican Staff: Are you using the engine timing lock tool set? You will not be able to set the timing without it. - Nick at Pelican Parts  
cuddles Comments: my bmw 318 sport coupe 53 plate oil light came on red right away with no warning put oil in it and drove 100 yards and it stopped sounded like a bag of bolts freind is a mechanic says sounds like it is the oil pump trying to save me money he says i should cut my losses and get a new engine as if they open it up and the garage find more wrong with it ,it will cost thousands
March 2, 2011
  Followup from the Pelican Staff: If you have the opportunity, you may wish to drop the oil pan and see what's going on in there. If not, then tearing apart the engine may not be the best move financially. - Wayne at Pelican Parts  
KTMRider Comments: I am planning to rebuild my '94 M50 TU engine . Is there a hook or mounting spot near the rear of the engine to attach the hoist . I plan to pull engine , TConv. and auto trans. as a unit .
December 22, 2010
  Followup from the Pelican Staff: There is a factory hook to support the engine, particularly when you're working on the bottom and have to remove the mounts. You use a bar that extends from the two shock towers and then supports the engine. I'm away from my office, so I don't have a photo of that from the BMW factory manuals. - Wayne at Pelican Parts  
Christopher Comments: Is there a definitive manual to break down and rebuild an M50TU engine?
November 14, 2010
  Followup from the Pelican Staff: Sorry, no I do not know of any resource that covers this, other than the factory documentation (which is pretty terrible in my opinion). - Wayne at Pelican Parts  
Rich Comments: I am rebuilding an 02 4.4 m62, I would like to freshen it up rings bearings and gaskets it was leaking from vanos and front timing covers, I was worried about the new rings sealing with the worn surface of the alusil cylinders there is @80k miles on the engine. no issues other than oil leak and noisey tensioner at start
September 2, 2010
  Followup from the Pelican Staff: You should be fine with the new rings on the Alusil block, 80,000 miles is not that much. You probably won't get another 100,000+ miles out of it, but it will last a while. - Wayne at Pelican Parts  
e60 2005 525i Comments: Hello,my BMW2005 525i was using a litre of oil every 500 miles. It was recommended I had new block and pistons fitted. After the work was done oil consumption didn't improve. I had a leakeage test done and the results were, Cyliders 1 and 3,4,5,6 with 5% leakage and number 2 being 12%. One of the plugs was so covered in oil they wouldn't tell me what cylinder that it wouldn't fire, they fitted an uprated oil seperator which as added an extra 100 miles before top up. Been told that I need new oil seals in the head. Any suggestions or opinions? thanks a lot
August 29, 2010
  Followup from the Pelican Staff: 12% leakage is a problem. They replaced your block and pistons without redoing the head? That's very odd, and a somewhat 1/2 quality job. I would have had the cylinder head completely reconditioned with a valve job prior to reinstallation. That will probably solve your problems. - Wayne at Pelican Parts  
bmw 328i 165k Comments: Hello, I have a 96 beamer 328i sedan. I am hearing a whining every time i hit the get louder when the engine starts cold and gets low when the engine is warmed up...another thing is a loud noise when im on the highway...i think its coming from the rear wheel but not sure...any suggestions I will appreciate the help..thank you
July 26, 2010
  Followup from the Pelican Staff: Take a listen with the hood open and see if any of the accessories are making any noise. In particular check to see if any of the fans is rubbing against the plastic enclosures. - Wayne at Pelican Parts  
deme Comments: i have a 94 318IS M42 coupe which i own it since 180k. now, after 1 year it has 250k and i try to keep it in good shape. if i drive sportoften, i shift only in 7000rpm. the engine is running smoothly, but i recently replaced the engine seal shaft because it was leaking about 1L/1000km. now its better but it still loses oil around the oil pan; is it hard to replace that gasket ? it is needed to remove the engine from the car ? beside this i have spent over 2000$ on other spare parts bushings,tie rods,bearings,clutch,radiators,water hoses-pump..etc
i realize this is a reliable car but in my country where im from the termic amplitude are from -35 to +42 and im expecting for another parts to break down. thanks
July 17, 2010
  Followup from the Pelican Staff: Yes, I believe it's pretty difficult to replace that gasket - you need to drop the suspension to get the pan off. You might be able to drop it down slightly and replace the gasket with the suspension still installed, but it will be difficult. - Wayne at Pelican Parts  
ph Comments: My bmw early of year 1994 e36 M50 325i mileage 259000 kilometer or about 131000 mile and I use bi-fuel gasoline and LPG together,pure gasoline is very expensive in my country Thailand before I fill with engine oil 10W-40 semi-synthetic I found some leak from crank gasket I change to fill with 20W-50 it is better but still drop but smaller than before and I plan to change this gasket later
July 14, 2010
  Followup from the Pelican Staff: If possible, replace this gasket. There isn't any other permanent option for repairing the leak. - Nick at Pelican Parts  
mauritiusblau Comments: It seems that the '94 was a great year for bmw! I have a 325is with 230k, with original clutch! Had no work done on the engine, and the compression test came back with excellent results. I try to keep a regular diy maintenance schedule. Too bad the plastic interior parts are not made as robust!
June 6, 2010
  Followup from the Pelican Staff: Thanks for the Info. We appreciate it.
- Nick at Pelican Parts
HPaul Comments: I have a 2001 330xi European delivery Today I drove to the health club and back to the house - did some computer work and went to drive to an appointment -- I tried to start the Bimmer and nothing - not getting fuel. I called my dealer and spoke with a technician... Based on my diagnosis he said sounds like to fuel pump! He directed me to looking under the back door on the passenger side and tapping on the tank and see if it starts… Well I did and it did! So after 10 minutes I was on my way again – I had several stops and had to apply my new starting technique several times. So I am passing this along – I called the dealer back and got an estimate for a fuel pump replacement cost of $682.31 and if I DIY with parts from Pelican – Just under $200.00 of course it will take anywhere from 30 to 120 minutes depending. Now if rebuilding was as simple – the poor baby is a little on the tired side 249,849 miles, uses 1 qt / 6,000 miles, average speed 54.2 mph, gas mileage last 2 years 25.2 before 27-28 mpg. The last 150,000 miles where mostly driven at an average of 5,500’ altitude. What should I expect to pay to rebuild the tired motor? Any referrals of really good Bimmer mechanics on the front range in Colorado? Any suggestions on the suspension struts, etc. – it is a 330xi.
May 7, 2010
  Followup from the Pelican Staff: Here's the link to the fuel pump article:

Check out the article about the head gasket replacement - you can use that as a starting point for an engine rebuild. - Wayne at Pelican Parts
TidyTony Comments: HI.
I have a UK driven 1994 BMW 316i SE which is on 130.000 miles at the mo'
It never eats oil and run OK but every now and then when I pull off in 1st it starts pinking and has now power for a few seconds and then it shoots off as normal.
It does it in 2nd sometimes too...
Any idea what could be the problem with it ?
had a new fuel filter 6 months ago but its done 20.000 miles since then.
January 26, 2010
  Followup from the Pelican Staff: You could have a fuel pressure or volume problem. I would perform a fuel delivery system test. Check fuel pressure, volume and quality. - Nick at Pelican Parts  
Carchick Comments: My model of Bmw is a E36 model. I am looking to get any intel on the in's & out's of putting a Bmw 4.0 v8 into this model. Any suggestions?
January 5, 2010
  Followup from the Pelican Staff: I'm sure it can be done with a bunch of retrofitting. I haven't done the swap myself so I cannot be much help. I opened a post in our forums. A Pelican community member may be able to answer your question.
- Nick at Pelican Parts
dmac Comments: I have a 94 325is and i am proud to say that i never have to add oil between oil changes. This is the original motor with 212,000+ miles. I still brag about the car not burning or leaking a drop of oil. If every BMW motor was made like this one i would never buy any other car.Is their anything i should look at replacing to get the most out of the motor? The one problem i do have is the California smog check, i have to take the car for a spirited drive on the hwy to make sure the cat is nice and hot so it will pass. BTW Great article
December 31, 2009
  Followup from the Pelican Staff: I think you are doing it right. Just keep up on your fluid services and regular maintenance. The vehicle should last you some time. - Nick at Pelican Parts  
gabesz77 Comments: Hi! I have an '89 touring 318i with M40 engine.I think so it has never been a performance machine, but I use as everyday car. Now we are 427.000 km without motor rebuilding. oil consumption approx. 1 l/10.000 km. Is it normally? thanks
December 13, 2009
  Followup from the Pelican Staff: Cool deal. If that's 1 liter per 10,000 km, then that sounds very good! BMW builds great cars! - Wayne at Pelican Parts  
1997 BMW 318 TDS Comments: I've got a question that I haven't been able to get answered. I have a 1997 318 TDS with about 300,000 km on it. That's about 180,000 miles. I have to put about half a litre pint of oil in once every 6-8 weeks. Is that normal? I don't see any smoke or anything coming from the car. If I wanted to put a newer diesel engine in this car, like the BMW N47D20 with 116 hp, is it possible? You can't drive fast where I live from US but live in Norway so it's better to have a weaker engine to keep you from getting speeding tickets-my last one cost 1407 USD for about 15 mph over the limit. New cars are ridiculously expensive here 4-6 times the US, so I could just go to Germany and get a new engine without a problem.
December 3, 2009
  Followup from the Pelican Staff: Sounds okay, it's also dependent upon the number of miles driven too. Too bad about Norway, I'd be broke by now. - Wayne at Pelican Parts  
BMW 318 TDI '97 Comments: This is for Salvadorian619. I had that problem on another car, turned out to be the catalytic converter that broke into pieces and clogged the exhaust. When it happened, I was on the highway in Germany. I went from 180 kph to about 120 kph and then after a while down to 50 kph before I had to stop. Car had no power at all. Had to drive 800 km like that to get home and then fix it.
December 3, 2009
  Followup from the Pelican Staff: Yup, this happens sometimes. When the CATs are hidden, it can be difficult to find. The car performs great at idle and revs fine, but when you put some real air through the system, it bogs down. - Wayne at Pelican Parts  
Salvadorian619 Comments: hi, i have a 93 bmw 318i and i feel as if the car has no strength it feels weak. what could be the problem? also there is a horrible smell inside the car when i drive it. any ideas?
November 11, 2009
  Followup from the Pelican Staff: You might have a plugged exhaust or some other dirvability issue creating low power and an odor. i would not drive the vehicle with the odor. I would have it inspected to find the source.- Nick at Pelican Parts  
washes Comments: What does it mean when your compression values are high? I have an 88 325is with 200K+, and I'm reading 180 across all six cylinders. Normal?
October 20, 2009
  Followup from the Pelican Staff: That sounds pretty good! - Wayne at Pelican Parts  
Sukh320ic Comments: Hi, I have a UK model E36 320iC 94. I seem to be filling up the radiator expansion tank but water seems to disappear! No leaks underneath the car, no mixing of water and oil! Any ideas? I was going to try the radiator flush and then see if this makes any difference! Maybe even put some radstop in!? Any ideas?
October 1, 2009
  Followup from the Pelican Staff: It's normal for the coolant to disappear into the engine when you're filling it up. After it's reached it's fill, it will stop "digesting" the fluid. If over time, you're losing coolant, and you don't have any leaks, then you probably have a head gasket problem. - Wayne at Pelican Parts  
jond42 Comments: hi,
i am swapping the cams in my e36 325i 11/93 manufacture date
engine is M50tu
need to buy exhaust and inlet cam bearing ledges..cant seem to find these in your catalouge..?
cheers John
September 18, 2009
  Followup from the Pelican Staff: That would be a special order part. Give our sales guys a call at 1-888-280-7799 during the week, and they can look up pricing and availability for you on those. - Wayne at Pelican Parts  
msirhk Comments: My 735i has a main gasket leak and makes a rumble noise from the engine.. Not sure how to go about this, Used engine put in by a mechanic who sold me junk! :
September 2, 2009
  Followup from the Pelican Staff: Hmm, small claims court? Really, you probably want to take your car to someone that you can find via a recommendation and ask them what their opinion is. It may also be nothing too... - Wayne at Pelican Parts  
naz Comments: Congratulations ACW!my 318is is up to 155,000miles now but unfortuatley has had many issues along the way!
June 24, 2009
  Followup from the Pelican Staff: Thanks for the Info. We appreciate it. - Nick at Pelican Parts  
ACW Comments: Hello,
I have owned my 1996 318is since new.
It now has over 350,000KM on it and it is still running strong and on it's original clutch!
I have had very few issues with this car. It does not burn oil, no leaks, and fuel consumption has never changed. What are the best things to watch out for as I move towards 400,000KM?
May 21, 2009
  Followup from the Pelican Staff: As the article states, keep a close eye on oil consumption, run a compression check maybe once a year, and keep changing the oil every 3000 miles or so. Sounds great! - Wayne at Pelican Parts  
magic Comments: hello, my 2002 525i is burning oil quite fast. for example I changed oil a week ago and already I had to add a quart of oil, and nobody can provide me with an answer why. as far as smoke, the smoke coming out of my car is clear so I have no clue where to start. please help me with some suggestions. thank you
April 18, 2009
  Followup from the Pelican Staff: Take a look at the oil separator and make sure it is not leaking and it is functioning correctly, you can use a vacuum gauge to check it. Look under the car for signs of an oil leak. Last do a compression and leak down test to see what kind of shape the motor is in. This will give you a place to start.
- Nick at Pelican Parts

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