Gave my car a service the other day and when i removed the spark plugs the one nearest the battery was dry black and sooty all the rest were fine, put the new plugs in and checked it after about 60miles and the same one was black.
Had my car in the garage where it came from for a failed CAT a few months ago, which caused a bit of damage to the engine, anyway got a engine rebuild and ever since then its been using a bit of oil, alot more than it used to.
My exhaust is getting really black with carbon build up too since then.
Tried in a thicker oil this time to see if that helps the oil useage.
But why is only one spark plug black??
Its the mk4 twinport (Z16XEP) engine, with a pipercross induction kit.