I know, in order to read plugs properly you must make run, shut off, remove plugs....I took my plugs out to install headers and noticed the spot below the elctrod on the white ceramic part oppostie ground strap. Not sure what this means. Pics below @ link.

http://i28.photobucket.com/albums/c2...her/car007.jpg

http://i28.photobucket.com/albums/c2...her/car001.jpg

 

Anyone??

 

Doesnt look like anything to worry about.

How long they been in there?

 

3 or 4 bottles. 2,000 miles. Every plug looks similar. Large brownish black spot oposite ground strap on porcelan below tip.?? Thanks for reply!