So, I changed out my plugs yesterday. Car runs very nicely.
However, for the first time, I took at look at the engine bay in the dark while the car was running, and all three of the rearward wires have small arcing from the boot shield to the block. I assume the front ones are the same, but don't know for sure since I can't see them easily. I never noticed this before the plug change, but maybe it was there. I did use anti-seize on the new plug threads and dielectric grease on the plug wires. Plugs gapped to .045.
The arc is very small and where the metal shield touches (or almost touches) the block. When I remove the heat shield from the boot, there is no arcing.
I have the original wires on the car (low mileage). Is this normal with the metal shield and to be ignored, or is this an indicator that the boots are not properly insulating any more and the wires needs replaced? A visual examination of the boots reveals nothing obvious -- they are still soft and have no visible cracks.
[This message has been edited by USMUCL (edited 02-28-2017).]
Okay, I did find some old threads discussing this topic, but there doesn't seem to be a consensus conclusion.
I'm seeing some state that the arc is a secondary pulse and harmless -- and that new wires didn't/won't change it.
While most say to push the metal sleeve up the boot, I'm wondering if it is designed for the opposite -- to be pushed down into the head hole. Doing so obviously stops the arc. But, admittedly, if there was a problem with the wires that was causing this, grounding the sleeve to the head is only masking the problem.
The sleeves are heat shields and also have a paper insulator between the boot and the sleeve. You might try removing the sleeve, smearing some silicone paste on the boot and reassembling with the paper and the sleeve. Pull the sleeve up away from the block.
The more I research, the more I'm convinced that that sleeves ARE meant to be pushed down onto the block.
When I google engine bay pics, the unmolested engine pics show the sleeve pushed down to the block. Even my Haynes manual, which has two large pics of an obviously new V6 engine, shows the sleeves pushed to the block.
The metal sleeves/shields are to protect the "rubber" boots. Push on accordingly. The arcing is caused by induction. It's normal.
Yep, and the "normalcy" of it is another reason I'm convinced the sleeves are supposed to be pushed down to the block (and thus avoiding this condition).
My plugs were the originals (I'm not kidding), and you can clearly see the line on the sleeves where they have been pushed into the head hole this last 31 years
Why are you concerned about "avoiding" a situation that's normal. It's not as if you're observing spark from the coil jumping to the heads... because that's not what's occurring. If it was, your engine would be running rather rough.
Don't watch your engine running in the dark if that inductive charge is freaking you out.
GM was still putting them on cars not to long ago. My 98 Camaro had the metal shields around them when it was stock. I also have an 03 Expedition that has them.
Plug wires are a lot better now than they were 30 years ago. I think those were to protect them from heat. Ive removed them with no problems.
Thanks, Roger. My car is very low mileage and still has the original wires. I would like to keep using them until they go bad. So, assuming the wires in 1986 "needed" the sleeves, I'll keep using them, too.
There is no arcing with the sleeves removed, and every cylinder I can see has this "induction" with the sleeves on ... with no detriment to how the car runs. Since it doesn't do it with the sleeves pushed down to the block, and since every picture of a new Fiero V6 engine bay I could find seems to show GM pushed the sleeves down into the hole to touch the block, I conclude this is how they were meant to be used. Heck, they are the EXACT right size to fit snugly in the hole (Insert "that's what she said" joke here).
The sleeves fit into counterbores in the heads. Push them in all the way. If they don't fit snug, pry open the ends slightly so they fit more tightly.
I had aftermarket wires from the Fiero Store, and I had removed the shields from the engine. The boots crumbled and succumbed to the heat. On my next set of wires, I re-installed the shields. No more issues; but I also got better-quality wires at the same time, so I can't attribute the success to just the shields.
It's not induction, it's leaky wires. The insulation is no longer effective; time for replacement. With the engine running, if you mist water (spray bottle) on the boots, does that cause the engine to misfire?
The spark plug wires that I have have grooves in the boots that fit perfectly with the metal sleeves. Seems to be the plug wire manufacturer means to have the boots mate with the sleeves. I can't think of the manufacturer off hand, but Thomas, or something like that comes to mind. b
"Induction" may have been the wrong term for me to use, but with all due respect... it was not "leaky wires" that USMUCL observed. It was an example of corona discharge.
The sleeves fit into counterbores in the heads. Push them in all the way. If they don't fit snug, pry open the ends slightly so they fit more tightly.
I had aftermarket wires from the Fiero Store, and I had removed the shields from the engine. The boots crumbled and succumbed to the heat. On my next set of wires, I re-installed the shields. No more issues; but I also got better-quality wires at the same time, so I can't attribute the success to just the shields.
It's not induction, it's leaky wires. The insulation is no longer effective; time for replacement. With the engine running, if you mist water (spray bottle) on the boots, does that cause the engine to misfire?
Wires don't last forever.
Hmmmm, it would appear you agree the sleeves need pushed in. I agree that a spark seen at that point is certainly indicative of bad wires.
But the argument seems to be that even new wires will have this induction/corona if the sleeves are on and not touching the block. That would be the experience I found from other threads.
Unless you're just making the argument the wires are bad if they fail the mist test?
I'm tempted to pay the $50 and put the Taylor wires on -- and if they show induction with the shields on but not touching the block, everyone but Patrick has to contribute to my 'go fund me' page to reimburse me for the unneeded new wires
Corona discharge may be seen around automotive spark plug wires that have become worn. To limit corona as it causes electrical losses. Corona discharges can often be suppressed by improved insulation. It look like you have a leaky wires replace them like pmbrunelle said.
If what you say is true, why is there zero corona/induction when I remove the metal sleeves and use the boots alone? And why would I not be getting any performance problem when I can see it in all three rear wire boots?
[This message has been edited by USMUCL (edited 03-04-2017).]
Ideally, with high-voltage conductors, there should be a large distance separating the conductor from grounded objects to prevent arcing or corona discharge. In that sense, the sleeves should be removed.
However, the engine is hot, and without the shields, the boots will degrade. The sleeves protect the boots from radiant heat emanating from the heads, block, and environment.
The sleeves are a necessary evil; required for thermal protection, even if they may provoke arcing. With the boots' insulation in good condition (cannot be visually inspected), there won't be arcing. If the insulation is failing, then the water mist will cause arcing (can be seen at night), or even misfires.
You can always try running without the sleeves; your boots may fare better than mine did.
Why would anyone not push the sleeves in all the way?
[This message has been edited by pmbrunelle (edited 03-04-2017).]
What is being confused here PM, is you're saying that the shields should be pushed down - but doing so stops the corona you said shouldnt be happening in the first place.
Alright I'm gonna buy the Taylor 74224s. I will install the metal shields and pull them away from the block to see if the corona is visible. Hopefully we can use that result to put this to bed over whether the visible "arc" is indeed indicative of leaking wires. If the new wires do it, we know it must be normal and I will assume the sleeves SHOULD touch the block to prevent it.
If the new wires don't do it, the only remaining debate will be whether the sleeves should touch the block.
The new Taylor wires do it too with the metal shields installed. Just not quite as bad.
I realize the spark created by the metal shields probably ain't "an issue," but I went with the Vulcan fiberglass heat shields instead. I get the heat protection, no arcing/induction/corona . . . and I think they just look cool. $24.50 shipped on Ebay
[This message has been edited by USMUCL (edited 03-11-2017).]
You should have seen my 93 LT1 Camaro with the Opti-Spark ..... Even with the best wires that money could buy at the time.....at night it looked like an electrified octopus was trying to hump my engine.....lol Its is just the nature of the Opti-Spark system and everyone has the issue with that setup... It was a sight to behold....kinda like the scene in the movie The Wraith when the engine decklid comes up and there is electricity coursing all over the engine.
It's not as if you're observing spark from the coil jumping to the heads... because that's not what's occurring. If it was, your engine would be running rather rough.
