Oil on Spark Plug Threads

[TheFLiP]

I tried searching through the forum but it returns a ton of irrelevant results.

As the tittle says, I found some oil on some of the spark plugs (two on the driver side, one on the passenger side) when I changed them out this Friday night. The car has +90k miles on it and most of those miles were driven hard and highway. Doing research, I found non-370 specific website diagnosis from ghasket covers, spark plug seals, to faulty piston compression rings.

The car does not have a rough idle and I don’t seem to be burning oil (that I’ve noticed). I’ll take a better note of it this coming month.

Has anyone dealt with this on their 370Z and how expensive or difficult is it to fix? I tried for an hour to look for Z specific forum posts but the words oil, spark, and plug returns a ton of unrelated results.

My last ditch is to have the dealership address the issue during the 90k service this weekend and bite the bullet on the cost. Any help or advice is appreciated. Thanks!

[jchammond]

Unsure if you removed the upper plenum when changing plugs; as you would have noticed engine oil in it...some guy’s are mounting dual catch cans between pcv & plenum & others are doing pcv deletes & venting to atmosphere.
It’s a good idea to view & clean out holes before inserting socket to remove plugs; as you could have a gasket seeping & causing some buildup on top side of plugs & wetness on them after removal.
Not uncommon to burn a little oil between changes; but keeping the oil from upper plenum will keep it out of combustion chamber & not allow it to gum up & lower octane rating of fuel.