Issue With Rich Fuel Mixture

[MPP147]

I have a 2017 540ix with issues. I live 1500 kms (round trip) from my dealership. After returning home from having work done, the engine light comes on. So far two trips have been made. It has been diagnosed that my cyl 3 is missing due to a high fuel mixture.

My first visit to the dealership found these issues:

- faults for crank case ventilation system
- cyl3 mixture deviation
- fuel vent valve faulty
- venturri nozzle faulty


Work performed replace fuel vent valve and second inlet.

There is no mention of work done to the Venturri nozzle. Is this covered in the work they did?


On my second visit the following was found:


- fault CYL 3 mixture control
- air leak at intake pipe on turbo charger


Work performed: replace intake pipe seal at turbo charger

No work performed on cyl 3


Shortly after returning home the check engine light has returned.


Can anyone offer suggestions?

[328 Power 04]

Do you have the actual codes that were read too?

[BimmerBreaker]

without codes we are just guessing, so my guess is not enough oxygen storage

[MPP147]

I'll see if I can retrieve them, thanks

[MPP147]

Here's the Code that pertains to my issue - 20E120.

I have other codes but they pertain to the cameras and seat ventilation.

[328 Power 04]

20E120 = crank case ventilation, ventilation hose: not connected/defect

[MPP147]

They replaced the fuel vent valve. The code was present after the work was completed.

[RBNetEngr]

Crankcase ventilation (CCV) is NOT fuel tank ventilation. It sounds like you have a cracked/broken vacuum hose under the hood that’s part of the CCV system.

https://www.realoem.com/bmw/enUS/sho...diagId=11_6425

[328 Power 04]

So is the ventilation hose still disconnected, or possibly damaged?

- - - Updated - - -

Also, is the mixture truly running rich?

If it is, then I'd have them look/replace that specific injector.
However, these cars will easily throw a mixture deviation fault code, so I'm at a bit of a loss what's going on, so far.

[MPP147]

I was told by two mechanic friends about the rich mixture and my tail pipes are showing telltale signs.

I could be wrong but work performed so far covers what should be a multi cylinder issue. Both visits showed that Cyl 3 was faulty. No work seems to have been done to that individual cylinder.