bouncing idle (throttle actuators & icv replaced) NOT FIXED | HELP

[e92_reaper]

I been chasing this problem for months now! To give a backstory and what I have done so far.

[2011 E92M3 6MT]

One cold morning, I was driving on the highway when the car started misfiring and I got a ENGINE MALFUNCTION message and CEL. Took it to my boy's shop and got the ignition coil and spark plugs replaced. To find out my car was still misfiring and extreme rough idle. I later took the car to a BMW shop (not dealer) they diagnosed a HUNG VALVE and BROKEN VALVE SPRING (cylinder 4 and it had low compression).

After getting the car back, the car drove normal but it buckles when it's at low RPMS however ROUGH Idle remains. It threw CEL codes for P0505 and 2B58 (which are for the ICV) I didn't want to spend anymore money having someone fix and diagnose the ROUGH IDLE because no one seems to have a clue on whats going on!

Reading in the forums here, people suggested the (TAs) Throttle Body Actuators and ICV (Idle Control Valve). I have Lifetime Warranty on my TAs and my ICV is new cause it was replaced a year before. (Maybe it be could the ICV )

Shoutout to M POWERSPORT in MI (Michigan USA) for being so cool and responsive I was able to receive the TAs quick!

Anyways I replaced the TAs and when starting the car it sounded a lot better! Now when driving the car does not buckled at LOW RPMS but the ROUGH IDLE remains. When coming to a stop and I'm in neutral with the CLUTCH disengaged, the RPMs bounces and then catches itself. To note I have a P3 Gauge and the AFR is sitting at 17 to 19 and erratic when idling.

I will have the video attached below, but when starting the car the Idle would sit normal at 750 RPM with AFR 14.8-15.6 for like 40-60 Seconds and then the RPM would bounce and catch it self before idling steady but my AFR is at 18 to 20.

https://www.youtube.com/watch?v=toPtXlPLM5A


Does anyone have any idea what can cause this? Thank you in advance!

[tldude876]

Fuel breather valve?

[e92_reaper]

Originally Posted by tldude876

Fuel breather valve?

Apparently the fuel breather valve was replaced too, worst comes to worst I'll have to purchase a new one to find out.

[e92_reaper]

Originally Posted by e92_reaper

Apparently the fuel breather valve was replaced too, worst comes to worst I'll have to purchase a new one to find out.

replace the ICV and fuel breather valve and the problem is still there. the idle is only bouncing when I'm coming to a stop and after I clutched in and rolling in Neutral.