What generally causes this? Pulled my plugs today and two out of three had small amounts of oil on the threads of the spark plugs. I'm assuming its not valve cover gasket or the grommets underneath it's clean above the threads. Thank you.
Following, I have the same issue on spark plug 2 in my 1994 Acty SDX. Hoping to figure out the issue!
Not familiar with how Honda handled the problem in how the recess is sealed from the head surface so can't be of help in that manner, but even a very very small amount of oil at the base of the plug would spread throughout the thread area as it was being unscrewed. Almost has to be just starting to seep into that area from the valve train area so look for how those two areas are sealed from each other. Fred
Thank you for replies. I looked inside of the spark plug chamber and tried to see if there was oil but couldn’t see any. As precautionary I changed the valve cover gasket kit which came with the valve cover gasket , spark plug tube gaskets that prevents it from leaking from the valve train side. Will pull my spark plug once I drive it again and will let you know if I find anything. I’m assuming if this didn’t fix it , it’s something from the combustion chamber side leaking oil into the chamber for some reason. Which doesn’t seem like an easy fix and will probably just keep driving it.
