I've searched and not found a answer so I though I would post. My #5 spark plug is covered in antifreeze, I can find no visible source of the leak. Any suggestions? Thanks, Shawn. Its a 1997 4.6l

 

is this on a 350 big block?

 

Its on a 4.6, forgot to add that.

 

Covered meaning coolant in the sparkplug well (external) or coolant on the plug when it's removed from the plug hole (internal)? I think you mean external but just want to make sure. Number 5 is the first plug at the front of engine on driverside. The thermostat goose neck and coolant outlet hose are almost above it. It is possible thats where the coolant is leaking and dripping down into the plug hole. The other possibility is in the same area but look at the intake gasket area. The gasket in that area can be a problem.

 

It is external, I cant see good enough to tell if its leaking above it or not. Tried to remove the goose neck but it feels like the bolts are going to break off when I try to loosen them. Going to try it again this week. Thanks for the reply.