cuto

anyone experiencing a rough idle in a 2008 535i? i seem to be able to reproduce the issue when i turn on the car, shift to R, and slowly reverse out. the car would chug along and vibrate . anyhow, i demonstrated this issue with the mechanic when i brought in the car for another issue (gearshift sticking, scary!) and his response was when i start the car, i shift to R soon after, and as i keep my foot on the brake the car is still playing catchup to bring the oil/fluid pressures up. is that a valid reason? i mean... this only started happening since maybe fall 2009 every once in a while and now it's almost fully reproducible.

FYI, this happens on warm starts too.

also, i'm beginning to notice the car idle rough while i'm at a long red light or big traffic jam. it's a slight tremor and i look at the RPM gauge but it doesn't fluctuate much. does that indicate some engine mount not securely tighten under the hood or something?!

or_550i

I've had this happen too in my 550. However, I noticed that it only happens after the car has been sitting unused for many days (4 or 5 days). It seems to be some emissions control related - I think.

Have you gone for a long drive (1+ hours) and still had the 'rough idle' the next day or drive?

Gene

HPFP...

tuffluck

i have a 530i and mine does the exact same thing...more noticeable though in the mornings after it hasn't been on for 12+ hours as opposed to just having a cold engine. i can kind of feel it in P, but when in R it is definitely more apparent. very odd...let me know your progression with the issue.

Munich77

My guess is HPFP or fuel injectors...

tuffluck

i don't have the 535i, so it's not that for me. also the guy with the 550i doesn't have those either and he had the same problem. sounds like it's something else...

cuto

what's HPFP? the dealer called back and they said they'll replace the fuel injectors. let's see how it goes. so... do you all think the mechanic's explanation is not valid then? i certainly wouldn't expect a car bought brand new would do this after 2 years of driving. :S

or_550i, the car is driven every day and i experience the chugging issue everytime i back out of the garage.

tuffluck

high pressure fuel pump, very common problem with the x35i engines as well as the injectors. consider yourself extremely lucky it hasn't happened yet in 2 years...

i really doubt that is it since i am having the same problem and do not have the turbo/hpfp in my car. let me know if the injectors fix it. when will they be finished? my car is going in for a stuck accelerator on saturday, so maybe i can give them your results if the injectors solve the problem. let me know! thanks.

cuto

the car is suppose to be back today. i'll give it a shot and see if it does fix the problem.

what's wrong with the defective HPFP then? what kinda experience would one have if they did have it?

cuto

oh ya... i read on another thread that you should occasionally drive the car hard to burn off the carbons in the engine, which may affect the tremor?!?! is that true?