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DIY Title: E36 Common Faults / Pre-purchase Inspection FAQ
BMW Category: 3-series E36
Author (forum name): Dudesky
Date Written: September 19th, 2005
Original Thread: http://www.unitedbimmer.com/forums/thread3824.html
Date Added to KB: November 28th, 2005

 
This is an attempt to compile as much of a list as possible about known E36 3 series flaws one might encounter. Keep in mind that these are known issues pertaining to design, production, or quality control, and in some cases, not necessarily recognized by BMW as such.

A little bit of background on the E36, which covers the '92-'99 3 series models (with some exceptions) . . . According to Bimmer Magazine, BMW E30 (and prior) engineers used complex math equations and heavy field testing to figure out required strength and durability, then they would double or triple the outcome, resulting in a fairly bulletproof car. Not so with the E36, which proved to be somewhat less reliable than the models before or after it, for two main reasons. The E36 is the very first BMW in history to be designed on CAD, and instead of extensive testing, they relied on the program to determine how robust a part or system should be. Secondly, they were engineered with recycling in mind. Which is a bit of an irony, since many owners can make these cars last upwards of 250-300 thousand miles. That isn't to say that the E36 is a shoddy Bimmer- they do more than live up to time honored BMW tradition, as the motors are quite strong, and light years ahead of the E21/E30 powerplants, along with numerous other significant improvements in comfort and performance.

Still, many of them were poorly maintained and abused by previous owners, and as they're currently approaching the higher mileage threshold, you can expect to spend a little money restoring one. But by no means should you not consider buying one, because it's an absolute thrill to drive, and tends to be more reliable compared to other cars in its class, despite its shortcomings. Furthermore, it should be mentioned that while the following list may seem frightening, not all E36's will experience these issues, and since they typically are higher mileage cars nowadays, a lot of the problems have already been addressed by recalls and previous repairs. On to the list . . . .


Engine Bay:

-There is no doubt that the most notorious E36 issue is the water pump. 6 cylinder models up to MY 97 were equipped with plastic impellers which would break apart and fail prematurely, stopping the coolant flow. Typical replacement interval is 60k, but theyve been known to fail at as low as 20-30k, and often randomly. Replacement pumps employ a metal impeller. If youre not sure that it was changed, do it anyway. Here's how.

-Clutch fan can shatter and cause extensive damage to the radiator, belts and other parts in its vicinity. A common preventative measure is to remove it using a procedure known as the Fan Delete Mod, but diligent regular inspection of the blades and timely replacement should suffice.

-The stock E36 radiator has plastic necks which can crack or break over time. Even if it looks fine, you may want to replace it, especially near the 100k mark, which is about the typical time when radiators fail. An alternative is to replace it with an all metal unit. The same goes for the plastic thermostat housing, aluminum replacements are available. Again, regular visual inspection is the key to avoiding costly damage.



-The fuel feed hose at the engine fitting can harden over time and cause seepage at that location. BMWs recall campaign replaced the hose and clamps.

-Engine ticking can occur, particularly with older E36s. This is characterized by a ticking sound (at idle) or the sound of marbles (under throttle) on the passenger side of the engine bay, most noticeable just after startup. It usually happens because engine oil can take some time to reach the VANOS and hydraulic lifters for lubrication. Most agree that this is normal, and is not something to worry about, unless you hear the noise all the time. In that case, the lifters may need replacement. The M50 was notorious for this lifter noise, and in severe cases BMW replaced the motor under warranty. However, on the M42, the problem is usually a failing chain tensioner, a relatively easy fix.

-Rough or poor idling is generally attributed to a dirty idle control valve, or a faulty oxygen sensor. But it can also be traced to the VANOS unit, which can get stuck in the advanced position, requiring a dealership adjustment or replacement.



-On some 93 and earlier M42 engines, which includes both the E30 & E36 318is, the profile gasket can be eroded by coolant, leading to failure anywhere from 30-70k mi. This is a costly problem since the cylinder head has to come off so the gasket can be replaced with an upgraded version. Although using only BMW approved coolant can help slow down the process, it does not prevent the failure.

-Some European variants of the M52 engine before MY 98 experienced premature cylinder bore wear, resulting in a loss of power and compression. This was attributed to the sulfur in gasoline, and the only solution is to replace the damaged alloy block. If you suspect you have this issue, have a compression test done.

-Drive belt idler pulley on some E36/M52 models may have been installed incorrectly during production, causing premature wear and eventual failure of the belt. This will occur during the first few hundred miles, characterized by excessive belt noise.

-Throttle valve can get stuck on some models, causing uncontrollable acceleration. This affected 1996 E36s (410,000 units), but other years may also apply. The problem lies in both the cruise control and throttle cables, where the plastic bushing on the cable end can break, allowing the cable sleeve to get stuck. BMW issued a recall campaign for this, and the solution was to install a spring steel retainer clip on the cable ends to prevent the outer sleeve from dislodging from the bushing.



-E36/M44 engines may have bad ICVs, creating a whistling noise, or causing a hard start or no start condition. The ICV was manufactured with incorrect tolerances between the rotary valve and the housing. The newer updated part number is 13 41 1 435 846.

-M50 engines with VANOS produced 1/92 to 8/94 may have problems starting in cold weather below 46 degrees fahrenheit, or in high altitudes. Symptoms include a check engine light, long cranking times, black smoke from exhaust, and wet spark plugs. When this occurs, the EPROM needs to be reprogrammed by the dealer (MoDiC programming software version 5.1 or higher).



Transmission & Final Drive:

-A faulty guide sleeve on the 1st & 2nd gear may cause the tranny to pop out of gear. Requires disassembly of the gearbox.

-On manual trannies, 2nd gear can completely blow out, or it may refuse to go into 5th gear when cold. Though very rare, this problem is expensive and requires a rebuild or replacement altogether.

-Squeaky clutch pedals are very common, the only solution is to replace the bushings with aftermarket parts, available from UUC Motorwerks.

-Stock transmission mounts can cause excessive vibration or movement, resulting in missed shifts and engine over revving. This problem is commonly referred to as "the money shift". A number of stiffer aftermarket mounts are available at Bimmerworld.

-Differential clutch pack retaining ring bolts can loosen or back out, eventually resulting in rear end failure. If you hear a ticking noise in the rear, have the final drive checked out.

-Some clutches shudder when 1st or 2nd gear is engaged while the car is hot, or has been driven in stop and go traffic for long periods. This is due to a non-asbestos lining on the clutch plate. BMW apparently has a new lining available; however some new owners continue to experience this shuddering.

-Flex discs (also known as Guibo couplings) can crack or shred prematurely. This coupling connects the driveline to the transmission. Characterized by a knocking under the tranny hump or a thunking noise under acceleration. Not overly difficult to replace.



Antilock Braking System:

-Faulty ABS pump motor relays manufactured prior to May 96 can trigger the ABS warning light.

-On rare occasions, the ABS warning light may glow briefly after turning on electrical accessories. This is a sign of a hardware problem with the ABS control module, which will need replacing.

-ABS rear wheel speed sensors on 92 E36s had poor solder connections. If the date code is 0801 (80th day of 1991) or older, they need to be replaced.

-On some 93 318is and 325is, six bolts which fasten the bottom cover of the ABS hydraulic unit to its housing may not have been tightened properly during production. The proper torque is 15 Nm. If its looser than that, the hydraulic unit is probably damaged and should be replaced.



Steering:

-Many E36's had the lower steering column replaced as a result of corrosion; there was a recall campaign for this.

-Power steering hose can leak. In worst cases, the condition eventually leads to hose failure, resulting in a loss of steering assist.

-Worn tie rod ends are often noticeable as a judder under braking. This is commonly mistaken for warped rotors as it has almost the same feel.



Suspension & Undercarriage:

-Rear shock mount failure is a very common problem, and can occur in as little as 20k miles. The symptoms begin with a dull clunking noise in the rear over bumps or rough roads, indicating that the shock piston rod has separated from the bushing mount. This can progress into metallic noises as the mount bolts shear off if not replaced in a timely fashion. The broken mounts eventually damage and tear the rear shock towers. Stronger E46 mounts along with Z3 reinforcement plates are recommended for replacement, and even better aftermarket parts are available from outfits such as Rogue Engineering and Ground Control.



-Weak front outer ball joints are typical on the E36. A common solution is to use stronger E30 control arms with ball joints preattached, simplifying the installation. All metal ball joints (Meyle) are another alternative, but at the cost of a slightly harsher ride.

-Rear inner control arm bushings are another weak spot, and should be upgraded to the tougher 96 or newer replacements.

-Under (but not limited to) heavy racing or track conditions, the rear subframe bushing mounts can tear off the body, causing extensive damage. Though rare, this typically requires welding reinforcement plates to repair the body.

-Rear trailing arm bushings can wear in as little as 50k miles, although there is debate on whether this is a fault or regular maintenance issue. Symptoms of bad trailing arm bushings include side movement of the rear end under acceleration, general looseness of the rear over bumps, and abnormal tire wear. United Bimmer has a DIY for this item. In a handful of isolated cases, the threaded holes for the console's 3 mounting bolts fatigued, allowing the console portion of the arm to break away from the car body.

-Some E36s may experience unusual wear along the outer edge of the front tires. This is resolved by replacing the upper strut to hub mounting bolt with an E36 camber correction bolt. Its smaller in diameter than the standard bolt, allowing for degree of camber adjustment. However, the dealer may not know what youre referring to, as the documentation on this part (#07 11 99 00 58 7) is very sketchy. Internet rumor has it that there are some sort of legal implications to this issue???




Electrical / Electronics:

-DME compartment flooding is a common problem for model years up to 94. Symptoms are hard starting or no start condition after heavy rain or a car wash. Insufficient drainage allows water to collect in the intake plenum cowl for the heating/AC, and overflows into the DME compartment. BMW issued a service bulletin with an easy fix for the situation.

-Earlier E36s had issues regarding defective ignition coils from Zundspule and Bemis. They were replaced with Bosch coils. If you still have the older brands installed, replace them right away. Cracked coils can seriously damage the ECU.

-Corrosion on electrical harnesses, particularly 2 and 3pin sensor wires, can result in erroneous readings and trigger warning lamps. Certain plug connections have a rectangular seal which comes off unnoticed, allowing debris to enter and raise the electrical resistance in the circuit, triggering a false warning. Often these problems are misdiagnosed. Some tin plated contacts have been replaced with gold by dealerships over the years to alleviate these issues. Problems include, but not limited to, oil level/pressure warning lamps, camshaft sensor, coolant level/temp sensors, incorrect fuel gauge & speedometer readings, and brake light warnings. Contact cleaner works well as a preventative measure.

-Voltage regulators typically fail on 318s fitted with Valeo alternators. The regulator can be replaced separately.

-Power windows sometimes behave erratically, moving up or down only in 1 increments. This is attributed to a magnet on the motor shaft falling out of position. The magnet can be moved back into position to correct this problem.

-A failing comfort relay causes the windows and sunroof to stop working inexplicably.

-In rare instances, owners have reported major wire chafing in the trunk harness, causing interior and exterior lighting failures and numerous blown fuses. Visually inspect this harness from time to time to be on the safe side.


-E36's with M42 engine and manual transmissions were recalled by BMW North America for incorrect routing of the oxygen sensor wiring harness. The wire could stretch and break, disconnecting it from the DME, and triggering the check engine light.

-A capacitor failure in the climate control module prevents the blower from operating while the AC compressor is engaged. The lights on the control module will also dim or go out completely. Fortunately, someone has figured out how to fix this without buying a new module.

-Glass breakage sensors on stock alarms supplied by Alpine can false trigger at times when the interior cabin temperature is high.

-Radio problems have been reported, most regarding dimmed or no backlighting. This is a dealer fix, but a better alternative is to replace the radio altogether.

-On some E36s, most notably the 95 M3, a faulty circuit in the safety relay can activate the hazard flashers and unlock the doors while going over bumps in the road.

-The heater element on heated seats often fails and needs replacement.

-Brake light switch failures are common, although there is debate on whether this is a quality control issue. Replacement is fairly easy.



Interior/Exterior Fit and Finish:

-Inadequate water drainage and/or rust proofing on some models causes rusting at the bottom of the front passenger side fender where it meets the door.



-Brake ducts on earlier models were poorly attached and can be dislodged or fall off. This also damages or breaks off the external temperature sensor, which is attached inside the duct.

-Early fog lamp lenses crack due to temperature related stresses, a warranty fix.

-Some dashboards bulge up at the center air vent. Inadequate adhesion causes delamination problems on door panels. Midrange and tweeter speaker trim cracks are also common.

-Glove boxes can sag over time, there is a fix for this problem.

-Rear door noises on 96 and later saloons are attributed to the type of rubber used on the door trim seals.

-Sunroof and rear parcel shelf rattles are common. Replacing certain parts in the sunroof mechanism fixes the noise, and you can support the rear deck with some foam stuffing to eliminate the rattle.

-Plastic headlight covers dull or get foggy. A number of compounds and polishes have been known to yield good results, but ultimately they ought to be replaced with the European glass units.


And there you have it, one of the best compilations of its kind on the net. This took some time to do, as I tried to confirm the validity of information as much as I could through research. But by no means is it the end all, be all . . . Feel free to PM me to add to elaborate, make additions or corrections to my points if you've experienced or know something that has relevance, as I may leave certain things out if I'm not familiar with them or have no experience on. This list will change over time as new info gets added, and newly written DIY links or photos are integrated.
 
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