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Looks like a brand new spark plug. How long has it been installed? If very long, its definitely running lean. Lean = high combustion temperature. Not good. As in melt a hole in the top of a piston not good.
One month. I know it was lean, had it tuned to fix that prior to finding a different oil leak. My concern is the oil on the spark plug nut and coming out the cylinder head hole.
No not fouled but pretty sure oil isn’t supposed to be there. Rebuilt 30,000 miles ago in 2005ish. Just found out today it has 1.52 comp cam rockers and some $2 pushrods. Top end looks pretty good from what little I know.
Well here's my take on this.
If oil is getting into the combustion chambers you will typically see oil residue all over the insulator and wet oil on the spark plug threads.
This is only caused by two things:
1.) Oil getting past the rings and up into the combustion chamber.
2.) Oil getting past the valve stem seal and leaking around the valve and into the combustion chamber.
Those plugs may have never been ran and just replaced in the motor and as for the oil residue around the spark plug holes that is puzzling.
No not fouled but pretty sure oil isn’t supposed to be there.
It's probably not oil, It's probably combustion gases (Carbon Soot) leaking past the threads on the plug. There is no way for oil to get there and not foul the plug.
Last edited by LLLosingit; Aug 30, 2019 at 11:45 PM.
Reason: spelling correction
Replaced and torqued myself. All plugs are a month old. The residue you see was there before I did the plug job and those plugs were old. Sure did look like oil at the top if the threads when I pulled them. Car was running super rich until I had it tuned. Literally tuned it, found leaking tranny and rear main, parked it and tore it apart. I’ve had the car two months and only got to put 349 miles on it, 340 of which were before the tune.
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