[SAM67]

Sarnman: my car was still under BMW's original 50,000 mile warranty and I had been experiencing a consistent engine hesitation in 4-6th gear (6MT) around 3,000 RPM when accelerating hard, e.g. merging onto the highway. I suggested to the service advisor that it could be carbon build-up in the intake valves. The tech did a test drive and confirmed the hesitation issue. They removed the intake to inspect valves and found "excessive carbon present." Took photos and submitted a PUMA case, which was authorized. The SA told me it was the first walnut blasting that they had ever done at that dealership (April, 2012). It didn't completely eliminate the hesitation issue but made a big difference. Not sure if your extended warranty will cover this but it never hurts to ask. Good luck.