keeps arcing through spark plug wires

[Ronger02]

Im on my third set of spark plug wires!

First, my truck started to run rough and misfire. It quickly got worse.
Opened the hood at night and saw all of the little blue arcs. The wires were old so i just replaced the spark plug wires. Two weeks later started to misfire again. I saw lightning jumping through the #5 plug boot to the header. This time I replaced all of the spark plugs and plug wires. The new ones are now starting to do the same. It looks like the #5 is a main problem again as well.

The question: is there a possible reason/problem with the engine causing this to keep happening or are the Autozone Duracrap plug wires just garbage that cant even last a month?

Thanks

 

[shane96ranger]

I have not had good luck with their wires. I was going through a set per year on my Explorer. I had some arcing happening, and their plastic keepers suck.

Try Rock Auto and see if you can get OEM's for it.

 

[shane96ranger]

I just looked, they have the Motorcraft wires for $28.79 for your rig. The part number is WR5996.

 

[Ronger02]

Ya, ill have to get some better wires, but I am still interested to know if there are any possible problems with my engine that could be causing this to happen?

 

[jfcasey]

Is your truck throwing any misfire codes? Is cyl 1 firing? If cylinder one has a no spark it could be your coils, but I can't say positively that would cause excess voltage to come down on 5..

 

[Ronger02]

The first time this happened I had a code cylinder #2. Second time code #5. No code yet this round and have never got a code for cylinder #1

 

[ryanthegreat]

check to make sure ur plug gap is within spec, and that the connection between the plug and the wire is good. i dont want to sound like captain obvious here but electricity follows the path of least resistance so either the plug gap is too big or the insulation in yer wires is weak and its easier for the spark to jump to the block.

 

[Ronger02]

Everything was installed correctly. I am not a rookie.. Autozone wires are just garbage. I got my money back and I have ordered a set of motorcraft wires

 

[vader436]

im no expert, but should you checked the coil?

 

[Ronger02]

Well, I ordered some new Ford Motorsport spark plug wires off of amazon. They seemed like they were made of a lot denser material. Installed them and been driving on them for a little while. Thought the problem was solved until today.

The spark is jumping through the #5 spark plug wire boot to the header again

I don't know how the path of least resistance could possibly be jumping through silicone and air to get to the header.

4th set of wires and new spark plugs

Yes, the spark plug gap is correct
Yes, the wire was connected to the plug correctly

Any ideas of what is going wrong?

 

[JP02XLT]

If you have one little cut / tear or thin section in the boot, the spark is going to jump, especially with headers installed and a closer grounding point to the tubing. Are you using the dielectric compound in the boot? Depending on the header and how close it is to the boot, you could easily be drying out the silicone boot, and it is losing its insulating properties. You might need to change to a 45 deg boot on that cylinder, I know the straight plug end is close on mine with the headers, although I have not seen an issue with cyl #5. I have ran Belden premium wires from Napa and they generally last about 2 years with the added heat strain from the headers, I can detect the slightest degrade of the wires with the SC. They also make some heat resistance sleeves to slip over the plug wires that might help you out a bit, I run it on my truck as the SC sits down tight on the valve cover on the drivers side and there is a ton of heat trapped in there. In the past when I have changed wires, the 3 on the drivers side are always toastier / darker than the 3 on the passenger side, I since added the sleeving and it is seeming to help with the heat issues. That might be something you want to look into as well, or change the plug style end on the wire.

JP02XLT

 

[Ronger02]

4 sets of wires have had the same problem. so there is no way they all had a little cut or tear in the same spot on the #5 cylinder.

No headers, stock manifolds.. pretty much stock everything

putting some sleeves on the wire boots might help, but there is still a root problem here that needs to be solved. It didn't used to have this problem and I would like to get it back that way rather than just putting a bandaid on the problem.

Thanks! Keep them coming!

 

[alwaysFlOoReD]

I used brand new wires on my race truck when I first got it running. The boots were toast within 2 hours of hard running....cheap wires.
Copy and paste from my build thread;
"I found my problem with why my truck was running rough. I had bought new wires for the truck three races ago and I have maybe 60 minutes of run time on them. Granted it's balls out running but I didn't expect to find this;

The boots, 5 out 6, turned into a disintegrating bubblegum type of consistency. I went to the local rod shop to get some good wires and they suggested I replace the boots, so I bought 6 MSD boots @ C$1.50 ea. I also bought a set of 8 kevlar socks for the boots @ C$40.00. It took me a few minutes to cut off the old and install the new boots and six socks. Total cost ~ C$50.00 which is still cheaper than a new set of high performance wires."
Edit; no headers, just stock exhaust manifolds.
Good luck,

Richard

 

[JP02XLT]

Im on my third set of spark plug wires! I saw lightning jumping through the #5 plug boot to the header.

This is why I thought you had headers on it, per your words, that's all we have to help you with, is what you type.

I guess I would take a close look at the plug, switch it to another cylinder to see if the miss moves, switch the wire with #3, In the Belden set #3 & #5 are the same length. Next would be the coil, you might have a problem there but there is no easy way to test them. Are you using the dielectric compound in the pug boots, it is there to help stop moisture and corrosion which can increase the resistance in the plug and lead to arcing as well.

JP02XLT

 

[Ronger02]

Well I think I fixed the problem. Thank you all for your input and suggestions I thought about the effect that heat had on those wires pictured above. It is the same kind of deterioration I was experiencing, except for the fact that it was only happening in one spot on one of my boots.. so I checked for an exhaust leak and there was in fact a concentrated blast of fire being blown on the boot!

1 new exhaust gasket
1 new bolt
1 new boot

Problem solved!

Thanks again