Two problems related to fuel injection have been reported for the 2008 BMW 5 Series. The most recently reported issues are listed below.
Reduced power from engine. Pressed accelerator and engine did not respond with regular power. Reduced power in traffic at 40mph. Pulled over shut off engine and restarted with full return of power. One repeat of problem 3 months later with similar results. Dealer replaced fuel injection auxiliary parts. Too soon to know if problem will recur.
June, 2010 - I was driving my 2008 BMW 535 station wagon on the highway (long island expressway I-495, new york) at 65 miles per hour when the car lurched, made a loud noise and lost power. BMW replaced the high pressure fuel pump. August 2009 - the car started but lights on dash board went on saying "vehicle had reduced power". It was towed to BMW dealership, where they replaced the high pressure fuel pump. August 2008 - the BMW lost power on the highway and was towed to dealer. They made a repair to the fuel injection system.