I have a 2006 Dak with the 4.7 HO. I was driving home from the store and I had a misfire issue, I figured I'd try to make it home and the engine completely died on me, we ended up towing it home. After reading codes I found an ignition coil g secondary circuit code. I replaced all of the coil pack and the plugs to find, when I come to cylinder 7, the coil pack was bulged and ruptured. I replaced all of the coil packs and do a quick road test and get a misfire and the same code on Cyl 7. I go to check the plug gap and the new coil pack was in the same shape as the old one, bulged and ruptured. I'm thinking there is a short somewhere in the wiring harness that is giving the coil power all the time instead of momentary. Anyone have this issue, or any thoughts?
Thanks!

 

Think I would check supply voltage for that coil pack, and resistance of the ground (control) wire. PCM fires the coil by interrupting the ground circuit.