Rough idle in park

loweredram · 07-08-2011, 05:11 PM

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 · 07-08-2011, 05:13 PM

carbon buildup maybe

gboop · 07-08-2011, 05:19 PM

Quote:

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 · 07-08-2011, 05:55 PM

Quote:

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 · 07-11-2011, 08:36 AM

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

Zasquatch · 07-11-2011, 08:43 AM

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 · 07-11-2011, 10:03 AM

Quote:

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 · 07-11-2011, 10:13 AM

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 · 07-11-2011, 11:18 AM

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

07-08-2011, 05:11 PM	#1
loweredram Lieutenant 51 Rep 415 Posts Drives: 16 F80 M3 Join Date: Oct 2010 Location: ca iTrader: (2)	Rough idle in park 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
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07-08-2011, 05:13 PM	#2
michaelalex17 Brigadier General 620 Rep 3,398 Posts Drives: Manual Wagon Join Date: Aug 2010 Location: CT iTrader: (4)	carbon buildup maybe
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07-11-2011, 08:36 AM	#5
AYF80 Major 82 Rep 1,142 Posts Drives: 2015 AY F80 Join Date: Sep 2009 Location: Nashville, TN iTrader: (0)	My car did this when it was Brand new... I added a AA BOV and it stopped.
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07-11-2011, 08:43 AM	#6
Zasquatch Captain 36 Rep 708 Posts Drives: '07 BMW 335i Join Date: Sep 2010 Location: CT iTrader: (15) Garage List 2007 BMW 335i [0.00]	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.
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07-11-2011, 10:13 AM	#8
Zasquatch Captain 36 Rep 708 Posts Drives: '07 BMW 335i Join Date: Sep 2010 Location: CT iTrader: (15) Garage List 2007 BMW 335i [0.00]	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.
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07-11-2011, 11:18 AM	#9
secretsquirrel Colonel 196 Rep 2,344 Posts Drives: f80 Join Date: Dec 2010 Location: Far North Dallas iTrader: (2)	I never realized that my car was idling rougher than normal until my HPFP was replace. Then it was baby bottom smooth.
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