[mcsweeto]

Twice today while making my way home from work, I experienced brief hesitation while under WOT. On one occasion I was in 4th gear, the other in 5th. Both times it happened, at some point as I climbed RPMs there was a short pause in acceleration and I could hear the BOV release. Otherwise it pulled strong, no stuttering anywhere.

Last week I changed plugs, I did coils last time. Car idles smooth and feels great. I haven't had a chance to pull logs yet but intend to sometime this week. Just wanted to get this out there to see what comes to mind before I can provide data.

-z
'15 435i
MHD Stage2

[auburnf30x]

Gonna need to pull codes and run those logs to get anything definitive. To me, it sounds like the car ran into some issues with knock and had to pull back the timing. I'd avoid pushing the car until you can run the logs and check for codes.

[edycol]

Full acceleration? High rpm's? Spark plugs.

[mcsweeto]

Originally Posted by auburnf30x

Gonna need to pull codes and run those logs to get anything definitive. To me, it sounds like the car ran into some issues with knock and had to pull back the timing. I'd avoid pushing the car until you can run the logs and check for codes.

Bringing this back up- work, other issues, and not having my OBD adapter caused me to put this to the side.

The problem is still noticeable, although I have tried not to push it. I changed plugs a couple months ago, I had replaced coils the last time, about 25k miles ago.

I will use Bimmetlink for logs, any readings in particular I should target?

[thejeremyman9]

Originally Posted by mcsweeto

Bringing this back up- work, other issues, and not having my OBD adapter caused me to put this to the side.

The problem is still noticeable, although I have tried not to push it. I changed plugs a couple months ago, I had replaced coils the last time, about 25k miles ago.

I will use Bimmetlink for logs, any readings in particular I should target?

If you heard the DV dump air as you said in your OP, it wasnt just a misfire, the DME closed the throttle. A misfire might be tangible in the car, but it wont cause you to dump boost. The DME has to actually intervene for that to happen. You need a "proper" datalog with all the logging channels to really understand what happened, most importantly you need pedal position, throttle position requested, throttle position actual, boost target, MAP boost, CP boost, and ideally WGDC, timing on each cylinder, and HPFP pressure and target. Standard stuff in MHD and BM3 logs.

[tyson20]

Similar issue for me just after buying my used 2013 328i xDrive. Previous owner had just changed coils and plugs. Found that one of the plugs had a hairline crack. Replaced plug and it resolved the issue.

[mcsweeto]

I have not been able to reproduce my issue. I have since learned the "don't do" of going WOT at lower RPMs which, in hindsight, is probably what was happening. Should have been downshifting instead of just flooring it.

While mine has not been terriby helpful in your case, I'm glad you were able to resolve your issue.