[drewsky1996]

2011 E92 328i N51 AT LCI, about 80k on clock right now. No aftermarket performance mods other than an afe cold air intake and muffler delete.

Going to scan the codes this weekend. Haven't had time yet. The issues I've been having recently are replicable, (which is good I guess). All issues started to happen the day after I swapped the stock steering wheel with an m-sport paddle wheel, (still have the airbag light on since I haven't had time to scan/clear codes), and I also swapped the stock front calipers with f30 brembos (this shouldn't have anything to do with the issues, but who knows )

The first issue is at idle in drive, the cars rpms will flutter or hiccup a little bit and lurch the car forward (not enough to hit the car in front of me, just enough for my body to move back slightly). Maybe some sort of transmission software/sensor?

The second issue is while cruising at about 30mph, if I let off the gas, stay in gear, speeds drop to about 20-25mph, then if I accelerate again about 1/4 to 1/2 throttle (not enough to make the computer auto downshift) I get this stuttering and hesitation until the rpms get over 2500, then the car feels perfectly normal again. (I know I shouldn't lug the engine like this, but it happens in traffic sometimes if I'm in drive mode). At first I thought this was an injector issue, but being tied to the other issues now I'm not so sure.

And the final issue in this trifecta is when accelerating quickly (usually from a stand still), at close to wide open throttle, once the rpms get close to redline, the car misfires (similar feeling to the stutter in problem 2, but causes a CEL and the whole car vibrates until I shut off engine and cycle the keys. After cycling, it's back to "normal". This to me seems like a bad coil pack/injector/combo.

Ill add the codes to this post this weekend when I can get up to the shop, but any feedback would be very helpful!

UPDATE: Scanned codes yesterday, cleared them, and will rescan this weekend.
2F7E - "Engine ECU: Engine Switch - Off Time, Plausibility"
29D1 - "Combustion misfire on cylinder 5"
29D9 - "Misfire at low tank fill level"

I am going to replace all the spark plugs this weekend when I rescan since they're due anyway. Hopefully that ECU code is being thrown because of the misfire, and not the other way around.

[geek]

I have a different car, engine, and transmission, but maybe this info will help. Mine (2008 328xi E90 6MT, 118k miles) started hesitating and lurching fairly suddenly one day about a month ago. At first it was only at low (< 2.5k) RPM but quickly became noticeable at all RPM. No check engine/service engine soon light, no codes (as read by Android Torque Lite app) nor any pending codes. I troubleshot going cheap to expensive:

• Cleaned mass airflow sensor - no effect
• Replaced all spark plugs - bingo

After replacing the plugs (the old ones were obviously shot--center electrode worn to nothing), the car ran beautifully for a few miles. The next time I started it up, though, it had a very rough idle and was shaking & lurching so much it was undriveable. The SES light was on, and a cylinder misfire code was indicated by Torque Lite. I cleared the code, and the problem magically went away...for just one trip. The next time I tried to drive, the misfire was back & clearing the code didn't help.

I pulled the misfiring coil & plug, swapped with another cylinder, double checked re-seating everything properly and haven't had a problem since.

Maybe your mods have the ECU confused and you just need to make sure you get all the codes cleared properly. Or you just need new spark plugs. Good luck.

[drewsky1996]

Originally Posted by geek

I have a different car, engine, and transmission, but maybe this info will help. Mine (2008 328xi E90 6MT, 118k miles) started hesitating and lurching fairly suddenly one day about a month ago. At first it was only at low (< 2.5k) RPM but quickly became noticeable at all RPM. No check engine/service engine soon light, no codes (as read by Android Torque Lite app) nor any pending codes. I troubleshot going cheap to expensive:

• Cleaned mass airflow sensor - no effect
• Replaced all spark plugs - bingo

After replacing the plugs (the old ones were obviously shot--center electrode worn to nothing), the car ran beautifully for a few miles. The next time I started it up, though, it had a very rough idle and was shaking & lurching so much it was undriveable. The SES light was on, and a cylinder misfire code was indicated by Torque Lite. I cleared the code, and the problem magically went away...for just one trip. The next time I tried to drive, the misfire was back & clearing the code didn't help.

I pulled the misfiring coil & plug, swapped with another cylinder, double checked re-seating everything properly and haven't had a problem since.

Maybe your mods have the ECU confused and you just need to make sure you get all the codes cleared properly. Or you just need new spark plugs. Good luck.

Thanks for the info! I'm going to scan the codes tomorrow and update the post. Hopefully it's as simple as plugs!

[drewsky1996]

Originally Posted by drewsky1996

Thanks for the info! I'm going to scan the codes tomorrow and update the post. Hopefully it's as simple as plugs!

Updated Post with codes

[arciga18]

I just started experience the an RPM shudder / lurch when the car is in Park or at a stop light. Will keep an eye on this