BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > Stumbling at idle and weak warm starts??

Thread Tools Search this Thread
      05-14-2012, 12:53 PM   #1
Alan l.
Major General
Alan l.'s Avatar

Drives: F15 M-Sport
Join Date: Jun 2009
Location: East Coast

iTrader: (9)

Stumbling at idle and weak warm starts??

Hey guys,

My car has been acting alittle strange lately. First off i did a cold start the other day and got out of the car to wipe it down. Noticed the exhaust tone wasn't smooth like it usually is and sounds as if its sputtering a little. Got back inside the car and could feel the stumble every 5-10seconds and could see the rpm fluctuate slightly. I've always noticed the N54 doing this peridically maybe once every couple of minutes but this was more rapid. Figure the motor was cold and it go away when i warmed up. Drove around a bit until the engine was warm and the car felt normal but stumbling at idle was still there. Decided to open the car up to see how it feels and see if it would clear up on its down. Exhaust popped loud a few times after going WOT up and down the block and sure enough the stumbling went away completely. The car has been fine every since. Any ideas? Running fmic, cobb S1+, rpi exhaust with only 15K miles on the motor. 6MT

Another thing is that i'm also noticing on occasional warm starts, the engine would barely turn on. It does catch but almost sounds like it wouldn't and stall. Had my HPFP replaced last year and the car feels fine otherwise. Cold starts fires up right away too.


2015 F15 35i M Sport |||More Photos of my X5 here|||
Appreciate 0
      05-14-2012, 12:56 PM   #2
Private First Class

Drives: 2007 335i coupe
Join Date: Feb 2010
Location: Grand Rapids, MI

iTrader: (0)

Garage List
2007 BMW 335i  [0.00]
My rpm used to stumble at idle also. I cleaned my intake valves and that solved the problem. Since your miles are so low I would assume your valves are clean so maybe spark plugs or an injector on the fritz.

Good luck trouble shooting
Appreciate 0
      05-14-2012, 04:57 PM   #3
rmw04c's Avatar

Drives: 2011 SGM 335is
Join Date: Apr 2009
Location: Cloud 9

iTrader: (2)

Honestly that sounds like plugs to me...on my old Jeep and my waverunners a few good WOT runs usually cleared up similar conditions, but ultimately the plugs were fouled and that was it. The job's so easy you might as well try it. Can't hurt!
2007 E92 335i - Retired
2011 E92 6MT 335is - JB4, Stett CP, Synapse BOV, Wagner FMIC, BMS OCC, CDV mod, AFE DCI, AR DPs, Cyba Scoops, BMS Clutch Stop, P3Cars v2.1 vent gauge, LED side markers.
Appreciate 0


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 10:34 PM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST