[D1/K-G]

Hello there,

I have been surfing the forums and google to find an answer to the problem I have been having with my 2008 E90 Steptronic 335i (DCI, DP, JB4 Map 2). Since I could not find a similar issue or problem after hours of searching, I have decided to create a post for my specific problem.

It all started one day when I was driving on some back roads. I launched in 2nd gear, but hit the button at the bottom by accident and the car shifted back into first as I was partway through 2nd, which I tried to compensate for with a shift on the shifter... but then my foot came off the pedal but then back on... I don't even know what happened - it was one of those awkward moments where the step/button at the bottom completely throws you off mid run. Anyhow, at the end of this awkward series of motions and the car being under full throttle, it slammed into third *loud clunk*.

It ran fine after that under normal driving,however, when I tried to do WOT runs (I manually shift it at 6500RPM) going from 2nd to 3rd, the car seemed to shift either shift into the next gear and immediately stutter/bog/lose power to the point where it jolted me forward - and of course at that point I naturally let off.

That was a few weeks ago, and it has been doing it since the - but not all the time. I has done it going from 3rd to 4th as well at WOT now a few times. I reverted back to map 1 and it did it less, and also reverted to map 0 and it stopped doing it.

I can't tell whether it is a transmission problem, or something else, because the second I go to shift from 2nd to 3rd or 3rd to 4th is when it does it. I would describe it as a severe bogging/cut in power which feels rather violent. An additional problem showed up after I tried doing this a few times to replecate - from time to time, after doing this, it would start to run with nearly no power after, and it would just vibrate as if a few of the cylinders were missfiring but consistently misfiring - it's a consistent vibration. When I stop and restart the car again, it immediately goes away. I have my JB4 code clearing setting on, so I should probably take off to see what it would say - not sure if JB4 erases all codes, but it's not showing when doing a scanner reading.

My thoughts are it might be one of the following: fuel injector, spark plugs, ignition coils, HPFP, LPFP - or some issue related to the transmission since that's how it all started. I had the car walnut blasted today, and it still did this afterwards so I know that's not the issue.

Anyhow, sorry for the long message - thought it would be helpful to be more descriptive if I am going to get an answer.

I appreciate any input or advice.

[firemanjust1]

First you should turn auto clear off . If you need a new coil or plug there should be at least 1 cylinder misfire if you are getting cel or ses. I would start there ,these transmission are pretty robust under 500whp you should be fine unless you are launching hard alot. From my understanding if you start getting locked in gear or getting the gear symbol in dash then you should worry about the trans.