BMW 3-Series (E90-93)

Engines

Click the links below to see common problems specific to the engines available on this vehicle.

Editor’s Note: My mechanic – who is a BMW fan – calls these the “worst and most unreliable BMW ever made.”

Cooling system in general, especially if fluid is not changed every two years
Automatic transmissions can fail if fluid is not changed every 60k miles (despite BMW’s claim that they have “lifetime” transmission fluid)
In manual transmission vehicles, the “baulk ring” can make it difficult to select reverse gear
Hairline cracks in wheels – appears to be caused by hitting bumps (like speed bumps) while wearing run-flat tires
CEL for excessive torque converter lockup slip, due to failure of a seal on the torque converter
Miscellaneous electrical issues

Vehicles with N54 engines and 6HP19TU transmissions: May experience delayed engagement of the forward gears and a harsh jolt when accelerating from rest during the engine’s warm-up phase, attributed to bad Neutral Idle Control calibration for the Electronic Gearbox Control software (subject to TSB)
MY06-07: TSB – white flakes/powder appear to come from climate control vents, attributed to surface oxidation of the evaporator; evaporator must be replaced
MY08 and earlier vehicles with ZF automatic transmissions: TSB – transmission warning light may illuminate and log fault codes 4F81, 507B/507C, or 507D; attributed to low fluid level or internal pressure leak caused by a defective adapter seal between transmission housing and Mechatronic unit
MY08 and earlier vehicles with ZF automatic transmissions: Transmission fluid may seep through the Mechatronic sealing’s O-ring