#5 spark plug wire burned off

[Lofin]

I burned off #5 spark wire several times on 3 year 36.000 mi Warranty

now with 40.000 mi #5 piston in the oil pan about $18.000 Workhorse
said to bad to sad

Workhorse seid burned off wire and piston exploding is non related

[sknight]

Honestly that sounds like a lean cylinder. I'd have to see pics of the piston itself to say for sure but that's my snap decision.

Keep going up the ladder. All that documentation of an issue and now a broke piston clearly leans toward an issue. Good luck with it but don't lay down and take it even if you have to pay a lawyer to draft a letter. GM goodwills stuff all the time especially if you have documentation, I imagine WH will do the same thing if you get ahold of the right person.

[mfire1339]

I would like to link the bad plug wires to the broken #7 piston in mine. They shined me on at 19,000mi.

Mike

[mfire1339]

couple photos of mine. No lean condition seen

Mike

[gallopn'go4r]

mfire1339, looks like you may have had a wrist pin bushing failure or piston cap failure. No significate sign of rod to piston wall damage.

[DriVer]

I just recently dealt with a plug wire failure and this was a Taylor Wire. The engine has a BIG miss and on throttle application I was getting a backfire and severe loss of power. Having left off the shields and replacing the wire, all is well!

Point is that IMO a miss will make itself immediately known when you put the pedal to the metal. I am reluctant to subscribe to the possibility that a plug wire miss would cause a piston to fail in the short or long term.

[Lofin]

The piston is in ¼" to ½" Pieces cylinder wall messed up bad

[mfire1339]

My thinking is the wire failed and the cool fuel shrunk the piston causing it to crack into hundreds of pieces. Like a tempered window glass. We were coasting at the moment of destruction, about 60mph.

Mike

[mfire1339]

Lofin, Check these people out. Great prices on new complete engines shipped anywhere.

Welcome to Dahmer Powertrain Inc..

[FATMANAR]

DriVer, My o3 started missing on the way home from spring break. I was hoping it was a plug wire, but have not seen any arking. Did you??

[Lofin]

No just melted inside wire felt soft

[phredsee]

Having a brand new unit with several WH issues right up front and reading this thread along with the brake problems, makes me think I should be looking for something else. Are the 8.1L motors a common problem or is this isolated with just a few?

[mfire1339]

Mine is no problem while sitting in driveway.

Mike

[DriVer]

Quote:

Originally Posted by FATMANAR DriVer, My o3 started missing on the way home from spring break. I was hoping it was a plug wire, but have not seen any arcing. Did you??

You may not see any arcing by direct examination however some have reported that at night they have seen arcing. The best way to rule out an arcing situation is to pull the plugs and check them. The wet plug indicates a plug that isn't firing.

You will be breaking wires in order to remove the plugs so have a few spares available in the event you find the mis-firing plug or broken wire.