I was helping my brother change his plugs and wires on his 97 4.6 this weekend. Plugs from cylinders 1 & 2 had a little oil on the topside of the plug around the base of the insulator. The plug itself looked fine, for 90 K Any ideas where this oil came from? Is it a potential problem. we changed the oil a couple of weeks ago to the 5W20. Could this be too thin and be leaking from the valve cover gasket or something?

John

 

According to Chilton's , " An oil fouled spark plug indicates an engine with worn piston rings and/or bad valve seals allowing excessive oil to enter the chamber" (1-30).
Being that you only have 90K on your brother's engine, I ( and I am no expert) would think this is highly unlikely. Did you spill any oil while doing the oil change? Are the valve covers loose?

It will be interesting to see whta others say...

Good luck.

 

You have valve cover gaskets leaking. If you let this go too long it will start to miss on those cyl. Fix it.

 

my bet is you spilled some and thats where the oil came from

 

Guys,

Thanks for the replies. I think the cover is loose. The oil is only around the hexagonal portion of the plug. It is not below the threads or on the tip.

John