I took the vehicle for the following symptoms: 1.) long(er) crank 2.) engine malfunction, reduced power 3.) service engine soon 4.) heavy, erratic shaking and shuddering 5.) engine sounded like a union pacific train with loud pumping sound 6.) because of 4 + 5, decide to turn-off the engine or sometimes it just stalls before 7.) after reset, the car becomes drivable but symptoms will reoccur. 8.) able to recreate problem when I mash the gas after doing some research on an auto forum, I suspected that the caused of the problem was a failing high pressure fuel pump. The dealership kept the car for 3 days to run some tests and concluded that the fuel pump was the problem. Since they replace the part, the car has not broken down again. However, they introduce another problems. 1) the car's exhaust noise is much louder now 2) the car is less fuel efficient, lower miles per gallon 3) the car now has a turbo lag which was previously non-existent. This means BMW is falsely advertising the 335I twin-turbo has zero lag. This was true before they updated the car's software but is not longer true at this moment in time.

- Dublin, CA, USA