[Rm95]

Hi all,

I have 2011 e93 330i that's misfiring on cylinder 6 only. On cold starts it's rough and if I let it idle rough long enough on start up the engine light come on but goes if I switch the car off and on. If I leave the engine light on and take off it judders/hesitates really bad even when I drive it at normal road speeds.

So usually what I do is start the car up, let it warm up and at this point the EML light has come on, when the cars warmed up I switch the car off and on so the EML light goes off and I start my journey. The car then runs/ accelerates fine from what I can tell but when I stop at lights for example it idles a little rough but doesn't bring the EML light on if idling warm.

I first changed coil pack on cylinder 6, Still misfiring. Then I changed all spark plugs, still misfiring. Then I changed injector on cylinder 6 ( index 11 and coded to correct values) still misfiring. Spark plug on cylinder 6 had more soot than the rest.

What could it be? I really don't want to go to dealers but I'm about to throw in the towel.

Codes that come up:
Misfire on cylinder 6 (0029D2)
Misfire at low tank level (0029D9)

P.s. this problem persist throughout all fuel levels.

Also forgot to mention that a mechanic done a compression test on all cylinders and was not concerned.

[e91Owner]

Soot on the plugs due to incomplete combustion and those codes indicate an injector leak normally. If you take plug out of cylinder 6 from a cold engine after sitting overnight and it smells of gas, that's likely your culprit. I realize that you have already replaced it, but your symptoms are still pointing to the same issue.

Other than that swapping the ignition coils from 6 to another to see if the problem travels with the coil.

[4foothill]

Check your valve cover gasket, it could be leaking oil into the spark plug wells. Other thing to try is a walnut blast, the n53 gets pretty bad, especially cylinder 6 in my case.

When you replaced the injector did you use new seals?