11-20-2017, 02:44 PM | #1 |
Tombarra Stalker
45
Rep 66
Posts |
6MT Erratic Idle
Has anyone else had an issue with erratic idle (with a stock ECU)? My 6MT is about a year old, with 17K miles, and I've noticed a stumble at stop lights over the last couple months. Idle oscillates between 500 and 750 RPM, stumbling at 500. It was only occasional a couple months ago but it happens every time now. This happens with all ECU modes and doesn't seem to have anything to do with where I buy my gas. Until recently, idle was dead-nuts-steady. Wondering if I have a bad sensor somewhere.
|
11-20-2017, 04:17 PM | #2 | |
Captain
300
Rep 606
Posts
Drives: 2018 F80 Atlantis Metallic
Join Date: Jun 2013
Location: NH
|
Quote:
__________________
Past: 2018 M3 Atlantis Metallic/SS, Comp Pkg, 6MT
Past: 2015 M3 Austin Yellow |
|
Appreciate
1
Racer3544.50 |
11-21-2017, 08:09 PM | #3 |
Lieutenant
375
Rep 507
Posts |
I feel like this happened to my car once when it was about 2 months old (M2). Almost died, but then idled fine and hasn't done it since. Never had it checked out, but still odd.
__________________
Present: 21 M2C 6MT/Ford something
Past: M2 Mineral Grey 6MT Past: BMW e30 m52 turbo 628whp/558wtq |
Appreciate
0
|
11-21-2017, 11:14 PM | #4 | ||
Tombarra Stalker
45
Rep 66
Posts |
Quote:
|
||
Appreciate
0
|
11-22-2017, 07:40 AM | #5 | |
Major
254
Rep 1,391
Posts |
Quote:
|
|
Appreciate
0
|
11-22-2017, 08:30 AM | #6 |
Brigadier General
1003
Rep 3,396
Posts |
Yeah, sounds like HPFP and/or injector banks similiar to what they had with the N54 you reference above. Which BMW did resolve with replacements of the items above and software adjustments.
OP, as stated it can leave you high & dry at a stop light without notice once these symptoms start, thus getting it looked at by BMW sooner than later is prudent.
__________________
|
Appreciate
1
Racer3544.50 |
11-22-2017, 10:16 AM | #7 | |
Major
254
Rep 1,391
Posts |
Quote:
|
|
Appreciate
1
Racer3544.50 |
11-22-2017, 11:01 AM | #8 | |
Brigadier General
1003
Rep 3,396
Posts |
Quote:
__________________
|
|
Appreciate
0
|
11-23-2017, 12:32 PM | #9 |
Tombarra Stalker
45
Rep 66
Posts |
Alright... I was hoping to wait until my next oil change (2,000 miles away) but I don't want it to leave me hanging. I'll get it scheduled and report back. Thanks for the advice.
|
Appreciate
0
|
11-27-2017, 11:12 PM | #10 | |
Captain
247
Rep 640
Posts
Drives: G87 M2 [MT]
Join Date: Mar 2008
Location: USA
|
Quote:
Another potential culprit for erratic idle is a faulty or dirty MAF. |
|
Appreciate
0
|
12-22-2017, 11:21 AM | #11 |
Lieutenant General
18659
Rep 14,107
Posts
Drives: G82 M4C X-Drive
Join Date: Mar 2013
Location: Orange County, CA
|
For the record, mine turned out to be a bad ignition coil. Easy fix.
__________________
2022 G82///M4 Competition X-Drive - KW-HAS, EBC Bluestuff, Millway Race Camber Plates, Cup2 Connect*, PSI High Flow Midpipe, Lightweight Front Lip, M Perf Flow Through Wing Previous • 2018 F80 ///M3 CS • 2016 F80 ///M3 IG: Raging_G82 |
Appreciate
0
|
12-29-2017, 08:28 PM | #12 |
Tombarra Stalker
45
Rep 66
Posts |
Well, I took my car in 7 days ago and it's still there... Dealership was able to reproduce the problem and ID error codes but every time they test those specific parts, they come out clean. I didn't get the specific codes or parts out of them but there was reference to coils and the fuel system (not surprising)... They've contacted BMW NA to escalate the issue.
|
Appreciate
0
|
12-30-2017, 11:08 AM | #13 |
Tombarra Stalker
45
Rep 66
Posts |
Just got a call from the dealership. They found the problem and it's been repaired. There was a tiny leak in the intercooler that was causing pressure variance, resulting in fuel trim oscillation. They did a smoke test on the intercooler to find the leak.
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|