Oil leaking out of spark plug hole?

[chaseincats]

Interesting situation going on here today.

I drove the car for the first time in about a month and a half and noticed some oil droplets on the subframe below cylinder 1 (closest to radiator).  I looked up and saw a slight oil trail seeping out of the spark plug hole.  I pulled the plug just now and the threads are pretty soaked with oil and confirmed there is a slight amount of oil in the cylinder using a borescope camera.

The car runs great without any blue smoke - is my spark plug not in tight enough or does the plug need a new crush washer?  If I take a brush and clean off the threads will it make a better seal?

I know these engines are old and without being rebuilt will of course leak a bit but coming out of the spark plug hole is something excessive I feel.

 

EDIT: the valve cover gasket is about a year old and not leaking - just checked.

Edited January 17, 2022 by chaseincats

[Mark Maras]

 My first guess would be a leaking intake valve seal. You might be able to visually inspect the seals with the valve cover off and a bright light. I'd do a compression test on all the cylinders to see if #1 is significantly (10%-15%) lower than the others.

[siteunseen]

Another easy thing would be swap the plugs around to see if it stays on that same hole. I'd do plugs and wires no longer than it'd take. Best of luck, hoping it's something easy.

That crush washer could be "crushed"?

Edited January 17, 2022 by siteunseen

[chaseincats]

15 minutes ago, siteunseen said:

Another easy thing would be swap the plugs around to see if it stays on that same hole. I'd do plugs and wires no longer than it'd take. Best of luck, hoping it's something easy.

That crush washer could be "crushed"?

Good idea - just swapped the plugs, I'll let you know the findings next time I take it out

[kyle146]

Crush washer is causing it, mine has been doing it for a long time. As soon as I get new plugs and don't take them out to look at them, I never see a drop.