BMW 8-Series (E31)

Engines

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

• BMW M60B40 (840Ci MY91-95)
• BMW M62B44 (840Ci MY96+)
• BMW M70B50 (850i)
• BMW M73B54 (850Ci)
• BMW S70B56 (850CSi)

Problems

All Vehicles

• Cooling system:
  • Plastic radiators
  • Expansion bottles – can split without warning
  • Viscous fan – clutch-driven fan will wear out the viscous coupling and can cause temperatures to rise at idle; replacement of the viscous coupling is simple
  • Hose that runs from the cooling system accumulator to the heater system bursts for no reason
• PCV valve – symptoms include smoke at start-up or under hard acceleration, and a noisy idle
• Inlet manifold seals – symptoms include noisy idle
• Manual transmissions – synchros are susceptible to damage if fluid other than Dexron II is used

Certain Vehicles

• Early models: problems with hazard lights and turn signals have been attributed to the flasher relay or crash sensor control module