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 they’ve been known to fail at
as low as 20-30k, and often randomly. Replacement pumps employ a metal
impeller. If you’re 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. BMW’s recall campaign replaced the hose and
clamps.
-Engine ticking can occur, particularly with older E36’s. 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 E36’s (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 ICV’s, 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 E36’s 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 it’s 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 E36’s 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”. It’s smaller in
diameter than the standard bolt, allowing for ½ degree of camber
adjustment. However, the dealer may not know what you’re 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 E36’s 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 318’s 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 E36’s, 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.