GregK

I just replaced my spark plugs today. This is what one of them looked like. What does this mean? The rest were very clean.

I replaced my plugs today and one of these came out like this. This is driver’s side closest to the rear. What is happening here?

Arrie

Looks like the gap is way big like twice what it should be due to the electrode has burned away. If this is same type spark plug as rest of them the plug may have defective electrode material that did not last as on the other plugs.

Black build on the plug is probably result of improper fuel burning as the spark probably was compromised for the overly large gap.

I would also check that the ignition coil for this cylinder is the same as rest of them.

kajtek1

Run smoothest test and recheck new plug at this location.
Could be just weak plug, could be other engine problems.

GregK

Thanks, I replaced them with plugs from the dealer.