I just finished a tune up on my 1992 240 and removed the plugs and replaced with new one. I have attached a picture showing that 2 and 3 have a black coating on the outside, wereas 1 and 4 are completely clean. Any ideas on what has caused this.....maybe not tighted enough during last installation???

Thanks for you help

RedBrick

 

Sorry there is no pic.

Do you hear and Exhaust leak by the engine?

 

How do you attached a pic to this post?

Thanks,

Frank





[IMG]local://upfiles/4018/FC540847F2E44FC9BC3BD7767C18D97A.jpg[/IMG]

 

You could have an exhaust leak or it could be from oil leaking from the Valve cover.

You got the pic figured out.