Oil on the electrode side of the spark plugs!

[jac]

I just noticed, while troubleshooting misfires on cylinders #5 and #1, that the spark plugs (injector side) on most of the cylinders have oil.

Is this the end?! :-). Or just another "simple" seal replacement?

[80stech]

Those seals are part of a valve cover gasket replacement. I would use a factory BMW gasket kit AND grommets. Get the misfire solved first though.

[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?

[80stech]

I didn't understand what "injector side" was. Are you sure you are not getting oil on the plug when pulling them out ? Maybe concentrate on getting the misfire solved.

[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

[StephenVA]

+1^ on the solution to the age old issue of a failed valve cover gasket.

[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.

[ahlem]

If you have a fresh set of plugs, try them after you clear the codes and do a compression test. How many miles? Let us know the compression numbers. The image appears to show a direct injection motor. The M54 has the injectors farther up the intake manifold. Is it oil on there or does it smell like gasoline?

[jac]

Thanks, do I need a special tool, other than the BMW scanner or INPA software, to pull the compression numbers?

Also, I included the graphic in my previous post for illustration purposes of the "electrode side" of the spark plug. Sorry if that mislead you.

[ahlem]

You can get a compression tester pretty cheap at Harbor Freight or borrow one from Autozone etc. The software won’t give you the numbers.