Community Forums

bryanwwelsh · 09-08-2021, 11:37 AM

This has been posted on many times I know but thought I would share this experience. 2007 Winnebago Voyage. At 25000 miles it started loosing power. Read forums, tried cleaning AMF sensor, changed plug wires. Finally changed plugs and that solved. At 37000 miles had same issue. So blindly changed the plugs. No help. Upon further inspection (should have seen it when changing plugs but didn't) found one of the wires shorting to the manifold. This was my fault because when I changed wires at 25000 miles I must have let it rub against the manifold.

First two pics are of issue. Last is showing right way to install them. Watch those plug wires!

TandW · 09-08-2021, 11:47 AM

Quote:

Originally Posted by bryanwwelsh

This has been posted on many times I know but thought I would share this experience. 2007 Winnebago Voyage. At 25000 miles it started loosing power. Read forums, tried cleaning AMF sensor, changed plug wires. Finally changed plugs and that solved. At 37000 miles had same issue. So blindly changed the plugs. No help. Upon further inspection (should have seen it when changing plugs but didn't) found one of the wires shorting to the manifold. This was my fault because when I changed wires at 25000 miles I must have let it rub against the manifold.

First two pics are of issue. Last is showing right way to install them. Watch those plug wires!

Good info for the noobs looking around. Thanks for the refresher!

donr103 · 09-08-2021, 12:28 PM

They make insulation socks that go over these.. you really should add them..

SmilingSam · 09-11-2021, 07:31 PM

Quote:

Originally Posted by donr103

They make insulation socks that go over these.. you really should add them..

AGREE completely, the heat of exhaust will harden the boots on plug, ruin ANY wire cheap or expensive and then will maybe crack & possibly short to exhaust/block.

Funny, they do not sell single plug wires ????!!!!

Get the black thick (double thick) kevlar ones, ebay for $13, are impregnated with oil/carbon and have a 2500 degree rating and are long, but also keep wires away from heat sources as you have learned.

GL !

Mudfrog · 09-12-2021, 09:34 AM

Quote:

Originally Posted by SmilingSam

AGREE completely, the heat of exhaust will harden the boots on plug, ruin ANY wire cheap or expensive and then will maybe crack & possibly short to exhaust/block.

Funny, they do not sell single plug wires ????!!!!

Get the black thick (double thick) kevlar ones, ebay for $13, are impregnated with oil/carbon and have a 2500 degree rating and are long, but also keep wires away from heat sources as you have learned.

GL !

Did a quick search but didn't find. I thought I had read on here that "insulation socks" weren't recommended for the plug wires on the 8.1. That the oem metal insulators were to be reused if they didn't show signs of being burnt. If true, I wonder what the reason is?

My thinking is that they couldn't hurt and that adding more insulation might help to keep the Magnums going.

SmilingSam · 09-18-2021, 12:01 AM

There are actually 2 types of protectors, metal and kevlar.

I personally think the kevlar may work better, metal will quickly conduct the heat into the boot, whereas the kevlar will/may 'insulate' from the heat better ?
(btw, my mh already had single layer white kevlar shields, above ones much better btw - previous owner ??)

Put it this way, racers use these for protection, they also wrap their exhaust with kevlar tape to protect/shield components and contain heat for mo power, so why not RVers ?

Here are the double layer black (red and blue ones also) ones I have, ebay $13.49 (url was too long so here is description, use search):

8PCS 2500° Spark Plug Wire Boots Protectors Sleeve Heat Shield Cover For SBC BBC

metal 'shields':
https://www.ebay.com/itm/31325978429...cAAOSw8SthJ5MR

Some wires can be bought with the metal boots btw, I bought 8.5mm wires non metal instead, actual metal wires not graphite (normal cars) for conduction.

GL!

Quote:

Originally Posted by Mudfrog

Did a quick search but didn't find. I thought I had read on here that "insulation socks" weren't recommended for the plug wires on the 8.1. That the oem metal insulators were to be reused if they didn't show signs of being burnt. If true, I wonder what the reason is?

My thinking is that they couldn't hurt and that adding more insulation might help to keep the Magnums going.

RealNiceTent · 09-18-2021, 02:22 AM

In the old days we used spark plug wires with ceramic plug ends for big block motorhomes from Champion, Jacobs Silicone plug wires were supposed to be good for 700 degrees. GM used a 10 or 11 mm plug wire on the Coil-Near-Plug engines for propane. GM uses the spring-loaded metal heat shields in most applications and they do work fairly well, however they are multi layer and the inner layer can burn degrading the heat barrier. Look inside the heat shield and if it looks burnt at all replace it. There are Kevlar boots that will fit over the top of them for extra protection and may even cover the whole wire in this application.

A side note here about spark plugs, my experience with GM engines since the LT1 is they are sensitive to spark plug types. By types I mean build composition, platinum, iridium etc. If the engine came with platinum plugs you have to use platinum or better, if you don't then there will be issues, misfires, pinging, coil failures, loss of power/performance. Sometimes even an upgraded plug, say Iridium for Platinum plugs will cause an unexpected misfire or something.