Dialectric grease necessary?

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to much thought into this,i squirt some in each plug boot hole slide it on the plug and call it a day,never any spark related problems,keeps the end of the plug from wearing(vibration)and helps the boot pop off easily.
 
Originally Posted By: brianl703
I'm not sure that heatsink grease is the same as dielectric grease. Heatsink grease often has zinc oxide in it to make it conduct heat better.

Or silver.
 
The shop manual for my 02 Ecotec forbids antisieze and says nothing about dielectric. I used a little of both when I changed plugs a year or 2 ago.
 
Yeah some plugs do not require anti-seaze. I don't use it much anymore myself. The ecotecs COP plug terminals are so well insulated I doubt they really need dieelectric grease.
 
Originally Posted By: brianl703
Dielectric grease prevents arcing. I used to (15 years ago) have an old IBM monochrome monitor. The flyback (which probably runs at about 10kV) started arcing. The arc actually burned a hole through the side of it. You could see it sparking and hear it crackling when the monitor was on. I applied some silicone caulk to it and that stopped the arcing. I probably could just as easily have used dielectric grease, but I didn't have any. The electrical insulating properties of dielectric grease are at least as good as silicone caulk.

Dielectric grease displaces air from the connection. Dielectric grease is actually a better insulator than air--and it also keeps water and dirt out of the connection. Air can ionize, once that happens, it conducts electricity. It becomes a very poor insulator! You could almost imagine that air is like a wall, and the voltage a battering ram. Once the voltage has gotten high enough to punch through that wall, there's a big gaping hole allowing all of the voltage in the circuit to leak through it.

Dielectric grease is a much stronger wall than air is. It does not ionize as easily as air.

I'm not sure that heatsink grease is the same as dielectric grease. Heatsink grease often has zinc oxide in it to make it conduct heat better.


I agree with all t hat and that was my understanding of dielectric grease. I was just commenting to the other poster about not using conductive grease.

I didn't mean that heat sink grease and dielectric grease are the same. Only that I think it could serve the purpose. My understanding was the grease conducts ehat better than air and the grese would fill the minute voids between the heat sink.
 
From my own observations plugs that have boots with dielectric grease used on them have much less corona staining at the base of the ceramic insulator.

I think the grease may actually help contain the voltage at the plugs contact and help prevent the spark straying to ground causing a possible misfire with these high voltage systems.

The plugs i see that have used greased boots have a shiny spot where the connector contacts the plug,which would indicate the connector displaces the grease on the connection.

Just a few thoughts,i have no idea but maybe an electrical engineer can comment.In any case i wouldn't want to change firewall side plugs on something like a GM van with a V6 that has dry boots and are seized on the plugs.
 
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Before I heard of dielectric grease we used vaseline or lithium grease. I still use lithium grease on light bulb bases and multi-pin connectors, esp. if they are going to be exposed to water. Even though all of these are technically insulators, connector mating causes the netal surfaces to pierce the grease flim to make a contact. The end result is a better contact than without it.
 
When I replaced the plugs and wires on my Taurus I made sure I used grease on the ceramic and a small amount of anti-seize on the threads.
Don't know if I will keep it for another 90,000 miles, which is when I did it the last time, but when I do I want to be able to remove everything.

Where does it say that cars don't require anti-seize on the plugs? This is the first I have heard of it.
 
Originally Posted By: SuperDave456
When I replaced the plugs and wires on my Taurus I made sure I used grease on the ceramic and a small amount of anti-seize on the threads.
Don't know if I will keep it for another 90,000 miles, which is when I did it the last time, but when I do I want to be able to remove everything.

Where does it say that cars don't require anti-seize on the plugs? This is the first I have heard of it.



I've read it on a NGK site before, but can't find it ATM. It said they use a special coating on their plugs and that the use of anti-seize is a bad thing since it will lead to over-toruqing, but I brush it on anyway.

http://www.ngk.com/glossary.asp?kw=Why+d...manID=1&pt=


^ this is the closest I could find.
 
I've always put a small dab of dielectric grease in the plug boot whenever changing plugs on my own, and tons of customers cars. Never had a problem from it.

I've also always put a small amount of antiseize on the plug threads and never had anything bad happen.
 
Dialectric grease?

I have a container of silicone grease with a brush top (same size and shape as my antiseize) that is marketed for brake hardware. It won't swell the rubber and I have used it on the plug wires with no problems. It is not the same thing I suppose... or is it?
 
Any of you who frequent TDI club will know that silicone dielectric grease was used to correct a MAF connector problem some years ago. The connector contacts have different metals and the grease prevents microscopic corrosion and subsequent added resistance which adversely affects the low-current signal.

Since that fix worked so well I have used the grease ever since on every electrical connection I take apart on car and computer. You only need a tiny amount right where the contact takes place. It does not increase the contact resistance at all - there is still metal-to-metal, it just excludes moisture from that area.

The only connector I had a problem with was an HDMI. Had to wipe it off to get it to work again at 1080p.

A 1980 Mercedes I owned had every connector stuffed with some sort of clear sticky grease and those where known to be very reliable cars.
 
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