320d E91 2006 MAF readings at 15 g/s idle

[igorguerreiro]

Hello fellow BMW owners,
This may seem a common problem with cars using MAF but it has been a headache since I bought this car 4 months ago.

The ECU is reading 15 g/s at idle (880 rpm). As result the exhaust is throwing white / grey smoke with "medium" accelerations. The MPG is low (33 mpg) and I know for sure this car can do 45 mpg with the same driving style (a friend of mine has one and I've driven it).

I've taken it to the garage and the mechanic measured the voltage of the MAF directly from the ECU and the values were correct. We tried with a brand new MAF and had the same result.
After that, the mechanic took it to the local BMW garage to try different ECU software versions, resulting in even worst behaviour.
The thing is that I'm reaching a dead end, only leaving me the impression that the ECU is somewhat corrupted, but even if it is, would it had accepted the software updates?

Any suggestions on this?

Thank you very much.

[MarcoZandrini]

15g/s, I’d correct, is waaay off. My old 3 liter M54 engine would suck in about 4.5g/s of air at 750rpm. What tool are you using to get this reading. I use OBDFusion.

The first step in diagnosing a problem is to scan the DDM (diesel engine computer) with proprietary BMW software. White smoke could indicate a blown head gasket. But, first scan the DDM.