Oil in Spark Plug Socket
#5
Let me guess, bank 1... either plug 2 or 3? Yeah, what these guys said. Most likely spilled oil. Only other possible cause would be a valve cover gasket. Or a bad pcv valve seal which I have seen. Allows oil to spew out and run down the valve cover into the plug wells. The head gasket is below the plug, impossible for it to seep oil into the plug well.
#6
#7
I had the #8 plug on my truck be cross threaded from the factory...last 145k miles...but for several thousand of those miles it had backed out enough to let gas exit and make a ticking sound. It actually sounded like the tick was in the bottom end. But when I had the plugs changed the guy said no more ticking...and the #8 plug was real loose and was all funky black in that area.