[Paxandrax]

I have an 07 328i, I was having MAF codes but I replaced the MAF and there was a vacuum leak from a bad valve cover gasket, so I replaced the gasket. CEL turned off after driving it a bit. But still having rough idle just not as bad as before. Also it seems like it wants to stall out and turn off on deceleration. Any advice on what to look for or fixes or even personal experience would be appreciated.

[EDWYER]

Might want to try new spark plugs.

[mainbearing]

Maybe the PCV valve diaphragm is bad. Is there is whistling sound under the hood? The plastic valve cover can crack too, leaking oil down onto the exhaust on the passenger side.

The 3-way PCV plastic pipe may have cracked. Usually that's replaced together with the valve cover.

Rough idle could also be the coils or the eccentric shaft sensor. Is there oil in the sensor connector?

https://www.e90post.com/forums/showthread.php?t=1988219

[e91Owner]

Originally Posted by Paxandrax

I have an 07 328i, I was having MAF codes but I replaced the MAF and there was a vacuum leak from a bad valve cover gasket, so I replaced the gasket. CEL turned off after driving it a bit. But still having rough idle just not as bad as before. Also it seems like it wants to stall out and turn off on deceleration. Any advice on what to look for or fixes or even personal experience would be appreciated.

Scan for codes and post here. If it’s as bad as you describe, it would be pretty rare for the DME not to store a fault.