Thanks for sharing your experience; please advise the diesel fuel brand you mostly used. Obviously you drove a lot (highway?), so not sure if the preferred brand was always available to you.
I actually liked dealing with BMW Gallery of Norwood.
I did all my research on the 335d and read about their carbon build up issues. However, it did not deter me from still purchasing the 335d. However, I had to buy one with CPO warranty.
I hope BMW gets to the bottom of this "technically". What in the world is causing this carbon build up bullish!t. They need to redesign their parts to resolve this issue!
My car is also at the dealership now for 4 weeks. Started with check engine light for injector failure. So far injector was replaced and they advised check engine light came back. So BMW NA told them to replace the computer. That seems to have fixed the check engine light issue...however, they did not release the car yet since it didn't get its blessings from BMW NA. They want the dealership now to replace the high pressure fuel pump (not sure why).
I did bring up the carbon build up issues, cylinder head replacement, blah blah blah to the excellent Service Advisor's attention. The tech, who owns a diesel himself (not 335d) mentioned carbon build up is not the issue..."I have the updated EGR cooler..." Etc. I hope he is right about my car. I'll update the posts when I get my car back.
The 335d is an excellent car and its very reliable. BMW needs to focus their attention to permenantly fix this 1 issue (carbon)!