x35i N55 erratic idle

[LFC]

Hey guys, after 2 weeks or so getting used to the 135 i noticed that idle was quite rough and fluctuates particularly noticeable when sitting in traffic, I can feel that slight movement in the seat.

After doing a carbon clean it was noticeably better but still there. Another thing was the real time fuel consumption when coasting with foot off the gas would not always be 0. Might have been over fuelling?

Booked it with BMW and they diagnosed the MAF as faulty. Part was not in stock so had to leave it there

Anyone have a similar experience?

 

[Dean ///M]

It's normally the connector to the Maf, simply clean it up or spray some Q20 on the connector pins

 

[Javbrat-wp]

also low quality fuel

 

[Acheron]

I've had this with my N54 pretty much since day one. I've just learned to live with it :=):

 

[Lee335]

My 335 N55 had a similar issue , was booked in for 7 days and they had to replace all injectors and spark plugs.
This resolved my erratic idling

 

[George Smooth]

Any updates?

If the maf was faulty it would possibly read airflow when it didn't exist so it would pour fuel. It is plausable.

By now I would have changed the plugs myself even if the plan guys refused. Not sure if you have done this.

 

[LFC]

Turned out the MAF wasn't faulty, perhaps they just cleaned it as Dean mentioned.

They did however replace the crankcase breather hose which was brittle and probably leaking.

Idle is now stable for the most part, not sure if the brittle hose could have caused this?

 

[George Smooth]

Turned out the MAF wasn't faulty, perhaps they just cleaned it as Dean mentioned.

They did however replace the crankcase breather hose which was brittle and probably leaking.

Idle is now stable for the most part, not sure if the brittle hose could have caused this?

It would cause it, not sure about the fuel reading though.

 

[LFC]

By now I would have changed the plugs myself even if the plan guys refused. Not sure if you have done this.

I have not done this, idle seems to be sorted for now.

Will keep a spare set on hand for troubleshooting if this happens again.

It would cause it, not sure about the fuel reading though.

This also seems fine now