03-29-2013, 07:49 PM | #1 |
New Member
1
Rep 16
Posts |
Hunting Idle on cold start
I have a pretty decent level of experience with the M54 and S54/S62/S85 motors, and almost as much with the N54, but not much at all with the N52s (I don't really care for it as a motor). So I'm coming to you for some help.
My wife has an 2008 X3 3.0si with around 78k miles. She had an issue last year where the dealer explained that a valve spring had worn down, and as a result the valve itself slipped and bent. Long story short, we ended up replacing the entire head of her motor. Her car was running ok for a bit, however around November she started complaining about her mileage getting worse. I wrote it off as the gas stations around here just switching to winter blend. The other night I took it out and I noticed on start up it was hunting for idle. Not bad, but very much noticeable. Then today when I was standing outside the car and she started it up, I could clearly hear the car trying to smooth out. It doesn't sound like it would with a bad coil pack (and we had all six replaced when we did the head last year). I just ran some injector cleaner through it (RXP), but it isn't an issue the car experiences warm so I don't know if it just has some dirty injectors. Has anyone experienced anything like this (Google searches haven't been my friend on this one) and know the fix? I'd like to think it has nothing to do with the new head. Also, it doesn't sound like the lifter tick I've heard in other BMWs. |
03-30-2013, 10:06 AM | #2 |
Major
147
Rep 1,319
Posts |
How is your high rpm acceleration? If it is inconsistent, then it's valvetronic motor. I had similar problem on my x3. Idle and over 3k acceleration was inconsistent. N52s are good engines. My e90 had 132k without any issues, x3 approaching 110k.
__________________
2016 F80 M3 BSM with Black interior DCT/Driver Assistance/Executive/LEDs/Adaptive/Black Wheels
2014 F32 435i xDrive AW/CR 2014 F25 X3 M-Sport Carbon Black 2011 e92 335is 2007 X3 122k miles 2006 e90 330i 132k miles |
Appreciate
0
|
03-31-2013, 11:32 AM | #3 |
Major
147
Rep 1,319
Posts |
Thinking more about this, it may be your oxygen sensor. Bad oxygen sensor would set off your SES light though...
__________________
2016 F80 M3 BSM with Black interior DCT/Driver Assistance/Executive/LEDs/Adaptive/Black Wheels
2014 F32 435i xDrive AW/CR 2014 F25 X3 M-Sport Carbon Black 2011 e92 335is 2007 X3 122k miles 2006 e90 330i 132k miles |
Appreciate
0
|
04-03-2013, 09:19 AM | #4 |
First Lieutenant
23
Rep 316
Posts |
Have you checked it for codes? Dirty vanos solenoids can cause this behavior, easy to clean. My X3 ran like a bag of crap until I cleaned mine, now its like a new car! I swear by Ceratec as an oil additive as well.
__________________
2008 SGM 135i Cobb Stage 2 FBO
2008 TS X3 MSport KW V2 |
Appreciate
0
|
04-08-2013, 08:53 AM | #5 |
New Member
1
Rep 16
Posts |
Sorry I haven't posted back till now, been real busy with work. I checked the codes, didn't pull any. Top end acceleration is still smooth past 3k. It is about time for an oil change so I'll try the additive. Also ran a bottle of RXP in the last tank, still having the issue on start up.
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|