[loweredram]

Not a big deal but wanted to understand why. Ive been chasing this rough idle issue with my 335. its not horrible but it stumbles from time to time. I changed the plugs same issue car runs great but what i discovered is that when the car is in neutral or drive(with my foot on the brake) it idles perfect no stumbles . I read thru the How the N54 works and couldnt figure out why. Anyone got an idea

[michaelalex17]

carbon buildup maybe

[gboop]

Originally Posted by loweredram

Not a big deal but wanted to understand why. Ive been chasing this rough idle issue with my 335. its not horrible but it stumbles from time to time. I changed the plugs same issue car runs great but what i discovered is that when the car is in neutral or drive(with my foot on the brake) it idles perfect no stumbles . I read thru the How the N54 works and couldnt figure out why. Anyone got an idea

HPFP, Injectors, plugs, and carbon build-up are the usual suspects.

Also, did you do the golf tee mod? I've noticed that my rough idle improves dramatically when I reconnect the actuator in the trunk.

[loweredram]

Originally Posted by gboop

HPFP, Injectors, plugs, and carbon build-up are the usual suspects.

Also, did you do the golf tee mod? I've noticed that my rough idle improves dramatically when I reconnect the actuator in the trunk.

Just had the HPFP replaced and i just did the plugs. I do have the Golf tee mod . Ill try disconnecting it and see what happens. Totally forgot about the carbon issue as well. Thanks

[AYF80]

My car did this when it was Brand new... I added a AA BOV and it stopped.

[Zasquatch]

Any tune? My car idled horrendously with the Procede. That was my one and only complaint when running that tune. Cobb AP now, and idle is smooth as silk.

[Magic-Man]

Originally Posted by Zasquatch

Any tune? My car idled horrendously with the Procede. That was my one and only complaint when running that tune. Cobb AP now, and idle is smooth as silk.

I still have the rought idle w/my AP. Rough idle seems to be normal w/these cars.

[Zasquatch]

Really? Carbon buildup then? I am sure that my valves are pretty bad (50k miles) but havn't looked yet. All I know is that my idle used to jump between ~600-900RPM.... Took off my BSH OCC and it stabilized a little and would jump 600-800.... Took off the procede and installed the AP and idle is completely flat at 600RPM with no jumping at all.

[secretsquirrel]

I never realized that my car was idling rougher than normal until my HPFP was replace. Then it was baby bottom smooth.