7.3 liter Godzilla Engine Spark Plug Wire Issues

[Mr Miller]

Eagle5. Thanks for the advice. Have code reader already. Probably diagnose and change plug wire myself if no Ford service around. I can probably get a replacement one at any parts store.

[Eagle5]

Another factor which we might consider is from the increased horsepower that The Godzilla produces. At 350 horsepower, it is 45 more horsepower than the V-10 it replaces. Assuming that 10% of the engine's heat is released through the radiator and by directly radiating off of the engine, that would be an additional heat load of:

• 45hp × 10% × 745 watts per hp = 3,350 additional watts of heat, at full power

Could it be that when a big Class A heads up a long mountain pass giving it everything she's got, that the additional heat load is frying the spark plug wires made from "conventional" materials?
Just a guess.
Eagle5

[Mr Miller]

Plug wire failed… again! Heading east from Rapid City going up a long hill in 90 degree heat, plug wire on cylinder #2 started to misfire. Called Ford repair that replaced 3 wires previously. They would not hand me a wire so I could replace it under warranty. They said their technician needs to verify the faulty wire and replace ~ their first open repair slot … 3 weeks, 3 WEEKS for 1 plug wire, a 15 minute job! I bit the bullet and bought a wire and will replace myself. Any mods I can do to cool the plug wires? 4 of 8 have now gone bad. Wish me luck!

[Eagle5]

Hi Mr. Miller,
I totally agree with you; replace the wire yourself.
I wonder if Ford will come-up with a heat-shield for the wires?
Glad that you have the code reader.
Thanks, Eagle5

[Scotty B]

Asked about any further issues in a separate post, copying here as well:
Hi Mr. Miller:
Yes, we had another issue a few weeks back - again in middle of nowhere - Stonecliffe, Ontario right as we left our campground.
Kind of a funny story - now!
I drove 15K or so to Deep River where there was a Canadian Tire. Did not want to help, but told me about a NAPA store just down the road. They could not help, but ran a scan and told me it was cylinder #7.
I had all 8 wires replaced the first time, though only 3 and 8 were misfiring.
I did keep all eight, but did not mark the two bad ones!
We were about three hours to Ottawa and our next campground. I had watched the guy replace the original 8 and had experience removing the dog house, so I decided to give it a shot - no other options - in spite of never having changed a spark plug wire before.
I picked the three best looking wires from the original eight and asked the wife to pick the lucky one.
Was not too bad getting the bad one off, though not much room for my arm and the end on the plug was a little sticky.
I struggled for an hour trying to the end on the plug, before realizing there were three "posts" sticking out, not just two. I had been trying to get the end on middle one that was not the plug! I kept reminded myself of Einstein's Law of Insanity, but did pay any heed to it! Once I found the plug, it went on quickly and the top was a breeze. 4 bandages later we fired that mother up and away we went.
Interestingly, the error code cleared itself the next leg of our adventure.
I have a scanner now and 7 wires of which 5 are good. Hope I don't need them.
I have service scheduled for October at a Ford Truck Center and asked them to do the work as per the TSB, though that is not supposed to apply to my model.
The odometer is still in K's, but I am around 13,500 miles.
Saved again but the Grace of God and kindness of strangers.
Will add this to my post on the wires as an FYI.
I think if I have the same issue after the work in October, it will be time to sell the rig and see about compensation from Ford - it's way to stressful and the PTSD lasts for a while afterwards...
Good luck and safe travels!