Oil on the electrode side of the spark plugs!

[c-bass]

Originally Posted by jac

80stech: Thanks. The oil is on the electrode side of the spark plug, not on the connector side. And I always thought that the seals that are part of the valve cover gasket overhaul are for preventing oil from reaching the connector side, not the electrode side. Please would you confirm?

The valve cover gasket is 2 pieces. The inner gasket goes around the spark plugs to keep the oil out of there.






When it gets old it becomes like hard plastic and doesn't seal around the head properly








half of my plugs were filled with oil and I was also getting misfires

[jac]

Originally Posted by c-bass

The valve cover gasket is 2 pieces. The inner gasket goes around the spark plugs to keep the oil out of there.

...

half of my plugs were filled with oil and I was also getting misfires

In my case the rubber tube on the ignition coils is coming out completely clean. So I do not think the oil is coming from the top of the head. That is what I was trying to clarify when I said that the oil is found on the electrode side of the spark plug. The "electrode side" is the side of the spark plug exposed to the piston/injector in the attached diagram.

I also replaced the head cover gasket (all 3 pieces) about 2 years ago with original BMW parts... I guess I could have screwed that up (not seating the gaskets properly), but that would not explain why the coil tubes come out clean.

[oldskewel]

Originally Posted by jac

In my case the rubber tube on the ignition coils is coming out completely clean. So I do not think the oil is coming from the top of the head. That is what I was trying to clarify when I said that the oil is found on the electrode side of the spark plug. The "electrode side" is the side of the spark plug exposed to the piston/injector in the attached diagram.

I also replaced the head cover gasket (all 3 pieces) about 2 years ago with original BMW parts... I guess I could have screwed that up (not seating the gaskets properly), but that would not explain why the coil tubes come out clean.

I think the confusion came from your titling the thread with "electrode" (which I think is what you mean), and then in the first post, say "injector" instead of electrode.

Yes, if your coil tubes are free of oil, and if you have oil on the electrode side of the plugs (internal to the cylinder, isolated from the oil under the cylinder head cover / valve cover) then that oil is probably coming from elsewhere. There are a few options, including valve stem seals leaking. Having all of them equally wet would be a clue. Is it liquid, caked residue?

M54?

[jac]

Yes, it is an M54 engine. The oil was in liquid form, but there is also caked stuff on there. The liquid oil has dried out now (please see photos below). But the threads of the spark plugs are also quite dirty with dried out oil and tiny little particles of something solid.