Hi everyone,

My r56 with 70k miles has always used oil. Now I have more time to get to the bottom of it. I decided I would run a compression test. Car was fine other than burning oil. Now I am stuck with a misfire in cylinder 4. I swapped the coil packs and spark plugs, but still?
I am pretty sure I did not mess up the test also i got 150 psi on all cylinders.

Any ideas?

 

Probably the problem is the wiring harness. Check connector and socket for any rust or oil residue.

 

Remind us if plugs were retorqued to their proper values (and not just tight enough) and the gap was not change accidentally by bumping or dropping the plug from even slightly during removal. If yes on torqueing to specs and no on gap change, then do a systematic test: switch the position of the plugs and test for misfire location

Once these are checked off, then we'll move with you upstream of the spark plugs for diagnoses.