Compare the fuel trims with the engine idling (no misfiring) versus the engine under load (misfiring and poor throttle response).

Also, is fuel still leaking into the crankcase and what is the fuel rail pressure when engine is idling versus when revved?

 

Hey there - currently on vacation but before I brought the car to a mechanic. He has some new findings:

• he verified my prior obsevations (compression ok, no air leaks and so on)
• did a leakdown test : -20% on all cylinders!
• major pressure out of the oil fill cap (it bursted a rubber glove) while engine is running

Could it be that the timing is off? Or are there other possibilities left I could check first?

cheers

 

Confusing

Good cylinder compression combined with a bad leakdown test doesn't make a whole lot of sense.

If the mechanical timing were off and the pistons were not at TDC during the leakdown test, air should leak from the intake or exhaust not the oil fill cap.

 

Agreed - This makes also no sense to me…*sigh

Anyways, will bring it to another mechanic who has more experience with R56‘s N18 and hope for the best. If he also has no success I will rip the engine apart and see if I can find anything suspicious while replacing the piston's with forged ones and all other internals (which I have planned anyway).

Could it be that I have a faulty ECU - since it throws no codes? If so is there any method to check other than reflashing?

I really don’t want to throw my mini to the scrapyard…:(