hi all, i would like to ask some one to help me diagnose what's wrong with my 2002 X5 diesel. It has 75000 miles and it smokes like a battle ship! Especailly on hard acceleration and enough that you can't see the car behind. It is otherwise fully serviced and drives great. It sounds rattley on start up but other folks told me that is normal.Should i be worried about the amount of smoke? I tried injector cleaner and now stick to shell diesel. thanks for your help