[Sleeper340i]

So I'm just took out my spark plugs and every single spark plug is good besides cylinder 4 spark plug.

Do you guys have any guesses what the main culprit is? Been having oil leak problem for a while, even though it hasn't leaked in a month from what I've seen it's been on average .5L a week to two weeks lost.

Also Mechanic did testing on my PCV and the testing came out good so not sure what it could be.

[Sleeper340i]

Guess I'm going to start with a valve cover gasket, even though my PCV testing came out fine. Do you guys recommend replacing the valve cover too?

Also, is there any DIYs I can use from N55 or N54 to replace this? None on B58s I can find and not really trying to pay a grand or more unless I have to.

[Wires]

Any other signs of oil around that plug? Could have been an "oops" during an oil change and it ran into that hole.

[Sleeper340i]

Originally Posted by Wires

Any other signs of oil around that plug? Could have been an "oops" during an oil change and it ran into that hole.

There was some oil inside on the left side deep inside near where the spark plug goes inside. Besides that, was relatively clean everywhere else that I saw including when swapping the plugs out.

[Wires]

Originally Posted by Sleeper340i

There was some oil inside on the left side deep inside near where the spark plug goes inside. Besides that, was relatively clean everywhere else that I saw including when swapping the plugs out.

Just wondering. I had a similar issue on my N54, and it was from me spilling oil when refilling which ran into the one plug bore.

[kern417]

Do a compression test on cylinder 4.

[weehe126]

Originally Posted by kern417

Do a compression test on cylinder 4.

The oil is above the threads. It's from a VC gasket leaking down onto it. Or from pouring oil on it as mentioned above.

[kern417]

Originally Posted by weehe126

The oil is above the threads. It's from a VC gasket leaking down onto it. Or from pouring oil on it as mentioned above.

I thought I was going crazy because I couldn't see oil on the tips but I made an assumption

[mike082802]

Originally Posted by weehe126

The oil is above the threads. It's from a VC gasket leaking down onto it. Or from pouring oil on it as mentioned above.

good catch

[Sleeper340i]

Thanks for the help everyone will be changing out my valve cover gasket shortly down the road.