Oil leaking from #3 exhaust spark plug

[None_zero]

I've had this persistent oil leak on the exhaust side and I thought I had it nailed down several times once I found the half moon rubber thing under the valve cover leaking or the gasket itself once. (Both fixed) and this was one of the main reasons I dropped the pan and regasketed it was to eliminate it as a possible leak source as well even though the original Leak was from higher up. Last time I cleaned the surfaces So I could see where it would show up again there was a little line of dark fluid (presumably oil) coming from the #3 spark plug well on the exhaust side. I assumed this was probably feo. The gasket above it and wiped it clean but today I noticed wet oil on my exhaust pipe again and went leak hunting again checked my recent repair first pan gasket seems clean and fine. Valve cover gasket is good and half moon well seated and not leaking. Which brought me to this I wiped it off but there was black oily substance going down the right side of the well down to the block tag and then under the exhaust manifold down onto that L shaped connection that goes around to the intake 

sorry this Pic is upside down but there is where it runs up against the Bell housing dust cover and down. To drip on the exhaust and smoke off I've always had a bit of trouble from this plug I think it has been cross threaded in the past but this plug is newer and ever since I realized there was an issue there I've been very careful about how I install and remove it it can be difficult to turn it in or out by hand but the threads of the plug don't look damaged to me

Maybe I'm just being optimistic. It's possible I am not getting it seated well for fear of damaging the socket well threads. What should I do you think?

 

Edited April 4, 2023 by None_zero

[datzenmike]

 

This oil is from the block vent pipe. It only pushes into the block. Or is old oil from the valve cover gasket. For the half moon I would spray clean the head and the moon and then a smear of RTV on the moon and press into place.

 

 

 

 

The spark plug has a ring gasket that seals so nothing gets past it. That said IF oil is coming out it can only be during deceleration when cylinder vacuum sucks oil up past worn rings. If it smokes when slowing down on the highway then that's the cause.

[Stoffregen Motorsports]

Agreed. The spark plug looks too clean for it to be pushing that much oil.