I have a 2007 335i coupe with 88k on the clock. Recently I have been experiencing cold start up problems in the morning whereby on starting the revs fluctuate greatly and the yellow check engine light comes on. After switching off and restarting everything is fine until after getting up to normal oil temperature I accelerate hard past 5k rpm and again the check engine light comes on. I have a local indy garage run by a friend who today look at the codes and has suggested I have a leaky injector/s which sounds about correct with the symptoms described.
I then went to my local BMW dealership straight afterwards as I know there is a QEP on the injectors. They told me all 6 had been replaced back in 2011 prior to me owning the car and suggested I book in a diagnostics at a cost of 135 pounds.
My question is if it is the injectors leaking will they replace them again for free? I am very wary of dealerships and the costs involved using them.
Any suggestions/advice would be very much appreciated.