Consumer Guide's® Auto Editors have scoured repair bulletins and questioned mechanics to search for commonly occurring problems for a particular vehicle. In some cases we also give possible manufacturer-suggested solutions. In many instances these trouble spots are Technical Service Bulletins posted by the manufacturer, however, we have our own expert looking at additional vehicle problems.

Air conditioner: The air conditioner compressor will shut down if the belt slips, which can occur after driving through a puddle and can be fixed by bypassing the A/C lock sensor control module. (1990-92)

Dashboard lights: Several problems with the hazard warning lights and turn signals activating by themselves, not blinking, etc. have been traced to problems with the flasher relay or the crash-sensor control module. (1992-95)

Poor transmission shift: The synchronizers in six-speed manual transmission get damaged if anything other than Dexron II automatic transmission fluid is used, causing notchy shifting. (1990-97)

Rough idle: Engine idles rough due to knock sensor picking up noise from water pump chatter when transmission is in drive and the air conditioning is on. (1997)

Rough idle: Engine may idle too high or run poorly (accompanied by a check engine light) due to vacuum leaks in the manifold gasket and/or leaking vacuum plugs on the fuel pressure regulator. (1997)

This table lists costs of likely repairs for comparison with other vehicles. The dollar amount includes the cost of the part(s) and labor (based on $50 per hour) for the typical repair without extras or add-ons. Like the pricing information, replacement costs can vary widely depending on region. Expect charges at a new-car dealership to be slightly higher.

1991-92 850i: Airbag contact-ring locking tab in steering wheel assembly can break without warning, possibly causing wiring to break and preventing airbag from deploying in a collision.

1991-95: Malfunction or failure of cooling system component can result in significantly increased coolant temperature and system pressure. 1994: Remote activation device can close windows and sunroof from a distance greater than the maximum (6 meters) permitted by Federal standard.

1994-97 840Ci: Plastic housing on cruise-control or throttle cable could break due to environmental influences, coupled with vibration, leading to separation; could result in throttle valve remaining partially open.