Oil on rear drivers side spark plug?

[michaelreed]

Went to swap out my plugs with iridium and found oil (sludge maybe?) on only that one spark plug. Closest to driver. Any ideas why that might be?

 

[SkylineGTRracer]

More than likely this.
Oily spark plug @ 60k service - Toyota FJ Cruiser Forum
http://www.toyota-4runner.org/4th-gen-t4rs/100614-changed-spark-plugs-one-covered-wet-oil.html

 

[michaelreed]

Thanks Man. Looking like vcg/ O-ring. Electrode was fine. Bought it with 98k and has 104k miles now and haven't touched the coolant which is still full. Only smell gas/oil so hopefully an easy fix.