GM 8.1L Ignition Wire Problems

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Old Trucker

New member
Apr 29, 2006
Hi Folks

I have an '05 37 ft Holiday Rambler with the GM 8.1L. Within 5,000 miles (yes 5,000!) I had to replace the ignition wires. Was getting a misfire on hard pulls. Covered by warranty of course. Within 2,500 miles I had another miss. This one was so bad, I needed a tow, for just under 80 miles (in northern Briitish Columbia). Had to wait (or rather waste) two days waiting for replacement wires. GM covers them under warranty but it took a few phone calls and some rather bad language? :mad: to get them to cover the $300+ tow bill. Getting replacement wires was a hassle but more importantly, I was losing confidence big time in my rig.

GM acknowledges a problem with wire breakdown on the 8.1s caused by heat but they seem unwilling to do anything about it but replace them under warranty, until your warranty runs out that is. In desperation, I went looking for another brand of wire. I found them at Sudden Impact Performance (their website is

When I bought the wires from them, I told em that I'd be back, hammerin on their door, if the wires broke down again. To make a long story short, I've put 12,000 miles on my rig with the new wires and everything is just peachy? :) . They are a well built wire and nicely priced if you compare it to what GM wants for theirs. I finally have confidence that I won't break down in the middle of nowhere, at least not from ignition wire failure (now.... that generator is another story? :mad: ;D)

If you are having ignition wire problems, check out the Aurora wires. If you feel a miss, its likely an ignition wire problem. Oh, one more thing. Apparently (according to the garage I took it to) , the vehicle's computer doesn't always record an error message from an intermittent miss and so when you go to the dealer, they find no problem. Just trust me, if you have a miss on an 8.1, its those crappy wires!? ?

John From Detroit

Well-known member
Apr 12, 2005
Davison Michigan
Interesting, I have about 5,000 miles on my 8.1, no problems with the engine at all, Not a one, Small air conditioning problem, will be fixed w/in 34 days, (Appointment made, quick repair) few other issues (Same appointment) but not a single problem with the 8.1.. And I've pulled hard enough it sucked a quart of oil


Moderator Emeritus
Apr 8, 2005
I've had same problem with both a 454 and a Ford 460 but after 40k miles or so. Used NAPA's high end ignition set and no further problems.


Well-known member
Jan 22, 2006
MIce, Rats, and even cats have been known to bite into the wirings on vehicles that sit for a while. 
Very previlent in farm communities and shed storage.  Manufacturers fought this problem even back in the 50' and 60's.  Once it was even contributed to a bird.  No idea how to make it varmit proof unless it's steel or protected wiring.

Gary RV_Wizard

Site Team
Feb 2, 2005
Looking to buy a new home
A few people have had ignition wire problems with the 8.1L on a Workhorse chassis.  I don't think anyone has pinpointed why it seems to happen only to a few RVs.  It doesn't seem to be related to any one chassis model or motorhome body either. Very strange.  ???  But I'm glad to hear that the problem can be solved with non-GM wiring - that's got to relieve a lot of worry from your travels.
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