Pulled these out of a 2012 Mazda 3 skyactiv with 80k miles. Can anyone explain why one of the spark plugs have a little oil and looks black on the threads? The other three look good imo
>>17388178
Maybe valve cover seal is leaking near that plug and dribbling some oil on it.
Tips look OK, so oil is probably not coming up from cylinder.
Leaky valve cover gasket. No big deal.
>>17388238
>valve cover
>>17388241
>valve cover
LIFTER LID*
Dont worry about it, sand the points down and toss em back in
>>17388178
>put sbargblug in anus
If it was a valve cover seal wouldnt leak on top of the spark plug not the bottom? Or does it make a difference?