Spark plug #6 has oil in spark plug well

[MATEO7788]

Hi I have a 2000 s80 2.9 with about 198,000 and just changed out the spark plugs and when I got to #6 it had oil in the spark plug well. The car runs fine with one check engine code for a o2 censor, get about average gas mileage. I'm wondering if this is somthing serious or if it could be just a bad oil cap seal or run off oil because of it the only one having oil and its right in front of the oil fill cap?

[ThommyKent]

It`s for sure just oil from someone being sloppy filling oil

[ThommyKent]

You`re welcome.

[Roger_850T]

I would agree, likely sloppy filling. Also, the rubber gasket in the filler cap gets dry and brittle; replacements are cheap (under $1 if you buy carefully,) I just replace them every 3rd oil change. I'd clean it, replace the gasket, and see if the issue comes back.

Roger