So now I only drove 500 miles and this #5 coil has gone again!! I guess I'll have to tear out the entire wire harness to look for shorts. Any other suggestions??? I've tried dielectric grease in the connector, silicone spray on the outside of the connector, there is no water in the plug area. At $40 a pop, this is driving me nuts and costing me a fortune.

 

When your are in a misfire mode, try a wiggle test on wires in the area. That could pinpoint a wire problem. Let us know and good luck.

 

I think the problem with that is the coil is actually shorted already so no amount of wiggling will bring it back to firing. The code, P0355, is coil malfunction. The last one I replaced had a crack in the top, in the potting material.

 

500 miles is a very short time ,can you get warranty on it. Physical damage is a good sign that a wiggle test won't work. Search here for a TSB(TECHNICAL SERVICE BULLITEN) or call your local truck dealer and ask them and have your VIN ready. Good luck.

 

Luckily, Murray's Discount Auto provides a one year warranty on those coils.

Thanks, I will search for a TSB.