One problem related to power train has been reported for the 2008 BMW 5 Series. The most recently reported issues are listed below.
BMW 535xi sport wagon 2008- . . Driving on highway, icon came on above speedometer - orange engine/half black and on dashboard below navi readout "engine malfunction-reduced power. " from then on we had no thrust with gas pedal. Car went in for service and was supposedly repaired. This then happened four more times. Each time the car was in the shop and parts were thrown at it and each time we were told the issue was probably fixed but they really did not know what the problem was. The car was in the shop about 30 days since the original incident. Parts replaced were vacuum hose black, vacuum pump, pressure sensor,removed and reinstalled throttle, replaced all vaccuum hoses on 7/14/10, charged battery 7/27.