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Old 12-30-2011, 11:04 AM
jburke4689 jburke4689 is offline
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Location: Ellicott City, MD
Join Date: Apr 2008
Posts: 746
Mein Auto: 2007 335i
335i Engine Hesitation between 2500 and 3000 rpm

I have a 335i (8/2007) production 6sp MT. I noticed a hesitation and roughness between 2500 and 3000 rpm under acceleration. There are no SES lights or any other symptoms. The car would accelerate through that range well enough but it was very annoying. It is particularly noticable in 4th through 6th gear. In 1st through 3rd gear the car accelerated too rapily through the rpm range to notice the roughness unless you are looking for it. My car has had the HPFP and all injectors replaced under recall and I paid for new spark plugs about a year ago and it currently has 67K miles on it. Otherwise the car is great.

I had the car scanned and there is a single code stored, (2AAF, Fuel Pump Plausibility). I took it to the dealer and they confirmed my symptoms (I did not tell them that I knew about the 2AAF and the TSB) and said I need a new low pressure fuel pump, the one in tank. I asked my service advisor if they were sure. "Why is it only in that rpm range?" He said the low pressure fuel pump is variable delivery and at that rpm delivery, that is the issue. I said OK but "fuel delivery at 2500-3000 rpm is different at each gear and varies with load on the engine." He said "we are sure that is the problem. I said "OK, do the repair." By the way, the BMW service bulletin says "do not replace low pressure components for 2AAF without testing a lot of other components first."

I picked up the car after paying my $700 and started driving it home. After warm up, I started accelerating and the car was still doing the exact same thing. I immediately brought the car back. The dealer has had the car seven days now and just told me today that they have opened a PUMA case with BMWNA.

I am reserving my opinion of this dealer until I have the problem resolved. Everyone can make a mistake. I will update the post as soon as I have resolution.

Has anyone experienced the same thing?
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