Another black/oily #6 plug. Anyone figured out why it happens?

[rudypoochris]

For those suggesting valve cover gasket: can you explain how oil from above the spark plug hole (where the gasket in lives) finds its way into the combustion chamber (where the tip of the plug lives)?

It looks like both to me. If I had to guess.

[onebadmofo]

Ordering new injector today, not sure how good the spare one I have is.
Also looking into getting a new battery, been getting slow cranks lately too.

[Eleventeen]

For those suggesting valve cover gasket: can you explain how oil from above the spark plug hole (where the gasket in lives) finds its way into the combustion chamber (where the tip of the plug lives)?

Yes, this is why that theory doesn't make sense to me. For that to happen, the sparkplug would have to not be properly sealed against the head... which means you would also be leaking compression. The only way a gasket could cause this, is if the oil is pooling in the bottom of the spark plug well, which gets transferred to the plug while it's being unscrewed. Is that the theory?

[onebadmofo]

By the way - should I put anti-seize on plug's threads?
Also what goes between the plug and coil? Mine looked like they had something there, a white powdery substance was in every coil.

[lulz_m3]

By the way - should I put anti-seize on plug's threads?
Also what goes between the plug and coil? Mine looked like they had something there, a white powdery substance was in every coil.

Do not use anything on the threads, but the white powder is most likely die electric grease, which you should use when installing new plugs or coils.

[ChuckD05]

Yes, this is why that theory doesn't make sense to me. For that to happen, the sparkplug would have to not be properly sealed against the head... which means you would also be leaking compression. The only way a gasket could cause this, is if the oil is pooling in the bottom of the spark plug well, which gets transferred to the plug while it's being unscrewed. Is that the theory?

that is also my reasoning behind always discrediting the valve cover theory, as well as no oil above the threads of the plug... just does not seem logical to me that it could be the valve cover, but i have been wrong plenty of times before...

and my plug looked just like his and it was a leaky injector...

[Eleventeen]

that is also my reasoning behind always discrediting the valve cover theory, as well as no oil above the threads of the plug... just does not seem logical to me that it could be the valve cover, but i have been wrong plenty of times before...

and my plug looked just like his and it was a leaky injector...

The injector seems like a good theory. My car is a 09/06 build, which I bought w/ 35,000 miles and I'm not sure if any injectors were replaced by the previous owner. I now have ~80k so it's probably time I pony up for some new injectors myself, for preventive reasons if nothing else.

[onebadmofo]

Swapped out #6 injector, car runs better, starts like stock and after 300 miles or so there's not a drop of oil on the new spark



Thanks to everyone that said to swap out the injector!

[hoopvillian]

Thanks for following up, so few people do.