Arcing coil and spark plug..ever seen this?

So I thought I had the dreaded head gasket failure or even worse the cracked head problem that plagues late 3.4 5VZ. But I pulled the plug on the cylinder that was misfiring and see what looks to be arcing on the plug ceramic. Anyone else ever seen this? Am I correct to think it is a bad coil or could the plug be causing it as well?

 

Starting with replacing the plug would be a good idea

 

replace the plug and the coil. I wouldn't even second guess it. See how it runs after. The problem appears to be very apparent.

 

Carbon tracking. You need a plug and coil. The spark will just keep traveling down the same path now that it has started.

 

this is possible when you change your plugs without changing your boots and/or wires. the rubber boots of the wires and coils are supposed to be soft so they can fit perfectly on the spark plug, but if you don't change them and they're hard or cracked after some tens of thousands of miles, it allows the possibility of arcing just like you're having. that could be 1 possibility.

 

Thanks! New plug did the trick but I got a coil first thing today to be sure.

 

It will do it again in time if you don't replace coil

 

$62 for a coil?

What is a good source?

Rockauto has them for cheap, esp if I have to replace them after 10,000 miles code.

 

you don't change the coil, just the boot booooooooooooot