Oily/white spark plug, engine runs fine

[vwengineer]

Hey guys!

So I replaced my spark plugs today after 60'000 miles as per the manual. Engine was running fine before, no misfires nothing. It is still running fine with the new plugs.

However I am a bit puzzled about the color of the spark plugs, they all look a bit white which is normal I think since this engine runs lean (also my last trip was about 10 miles down hill so very low load) however one of the spark plugs also had some residues, which I believe are oil. This the cylinder 3 spark plug.

In addition the whole tread is oily up to the washer, the others do not have any oil there.

The engine has 210'000 miles, so I guess it could be piston rings, valve guides and/or maybe valve cover gasket. Also oil consumption has never been a concern since it's about a quart for each 10'000km.

Since the engine doesn't misfire, should I be concerned?

Thanks

 

[1131]

If it's the valve cover gasket, oil will drip down onto the coilpacks.
A compression test should tell you most of what you need to know.
A leakdown test is definitive if you have that tool.

 

[vwengineer]

Yes, there was little to no oil on the coils, but I fail to see how oil would find its was up to the entire spark plug thread, even if the cylinder was filled with oil.

I might do a compression test but as the engine is running good I am not sure if it's worth it.

Thanks for your answer