Which plug(*) are cracking? Front or back side of the engine?

Thats odd I've used 3 different sets of Autolites in my car 1.) Autolit 104 platinum 2.) 104 Copper 3.) Autolite 103 copper

I've found that the NGK'* seem to feel much better anyway.

Ed

Not to throw this thread in a different direction, but did you replace the spark plug wires when you noticed the carbon tracking? This question actually does have a serious side to it, it'* not just a pointless question.

The first time was Cyl #4 and now the miss is coming from Cyl #2. Naturally, this could not happen to plugs on the front of the motor. That would be too easy to fix. :?

No, the wires were almost brand new when I found the bad plug. It was one of the things I did trying to get rid of the miss before it finally threw a code and pointed me in the right direction. I didn't see the bad plug while I was replacing wires because it was in the middle in the back of the motor. Short of removing it, I could not see it. Since it was fairly new, I didn't have a reason to remove it.

I only ask because carbon tracking will transfer from wires to plugs and vice versa. I'm a little confused as to when you replaced your plug wires, but I think you can understand from my message what i'm suggesting.

Please explain further. I for one...am not understanding how carbon tracking and cracked plugs can transfer to different wires on different coils going to different plugs and would like to gain more insight.

I think I underestand. You are saying that the same carbon track that was on the plug is likely on the wire connector for that plug. So when I replace the plug without replacing the wire, that track on the wire connector could heat up or conduct oddly and score or crack the new plug as well, correct? In this case I did use a Q-tip and some dielectric grease to swab out the connector and clean it up as well as possible before reconnecting it to the new plug. As for when I replace the wires, it was after this problem started, but before I replaced the damaged plug.

Exactly -- I wasn't saying that the carbon tracking will transfer between different cylinders on different coils, as BillBoost was asking above. If you have carbon tracking on cyl # 5, for example, and only replace the spark plugs but use the same spark plug wires, you will end up with carbon tracking on cyl #5 again. Even if you cleaned the inside of the spark plug wire, from what I understand regarding carbon tracking, it'* actually in the rubber boot and you'll need to replace the wire to completly fix this problem.

This is the reason behind my question on the jumping wires. Engineer mentions it'* now a different cylinder. Therefore if the wire was the issue the problem should again be on cyl 4 not cyl 2 now.

The problem according to Engineer moved from cylinder 4 to cylinder 2.