A 4th COP has gone bad on my 2000 V10 Ex. I have decided not to get it changed and I will just change the 7 that are left on my own. I've read many posts about applying plenty of Die-electric grease, but not specifically where or how much is plenty. If I understand correctly, shouldn't I only apply it to the rubber boot and avoid any electric contacts? Thanks.

 

Put a shot of grease into the spark plug end of the boot.

 

Keep in mind dielectric greases increase resistance. Yes... they do help prevent corrosion but will also impede electrical conductivity.

Certainly OK to use after the connection is made but introducing a dielectric compound inside/between a connection is a bad practice. Think about it... most are dielectric greases are Silicone and Silicone is non conductive.

Electrical compounds that are conductive, and provide corrosion resistance, would be a better choice for a current carrying connections. The link below is a product that has been used forever without any issues and makes an excellent corrosion inhibitor. Can be used in many- many applications.

Sanchem NOOXID electrical grease & electrically conductive grease dielectric grease and contact lubricants

...just sayin'

 

Just put a tiny bit on the end of the spring in the boot, otherwise all you are going to do is attract dirt and moisture. It doesn't even need to be dielectric, people go overboard with that stuff.

 

Nope.

Conductivity is only going to take place where there is physical metal-to-metal contact. The grease will not stop that. All it does is prevent air and moisture from reaching that contact area and causing corrosion.

All it takes is a pea-sized (or a bit larger) amount of dielectric grease in the boot to do the job.

 

Please do not leave a bad COP in the circuit long as it can take out the coil driver in your ECU.

 

No, on the end of the spring.

 

And cops go bad because of resistance down the line (they need to "breath")

 

One Adam-12, One Adam-12, see the man!

 

If I'm wrong then you'll have to redefine electrical properties.

di·e·lec·tric
ˌdīəˈlektrik/Submit
PHYSICS
adjective
1.
having the property of transmitting electric force without conduction; insulating.
noun
1.
a medium or substance that transmits electric force without conduction; an insulator.

 

Wiki quote

"A common use of dielectric grease is in high-voltage connections associated with gasoline engine spark plugs. The grease is applied to the rubber boot of the plug wire. This helps the rubber boot slide onto the ceramic insulator of the plug. The grease also acts to seal the rubber boot, while at the same time preventing the rubber from becoming stuck to the ceramic. Generally spark plugs are located in areas of high temperature, and the grease is formulated to withstand the temperature range expected. It can be applied to the actual contact as well, because the contact pressure is sufficient to penetrate the grease. Doing so on such high pressure contact surfaces between different metals has the advantage of sealing the contact area against electrolytes that might cause rapid galvanic corrosion."

Petroleum or a petroleum containing product as mentioned will deteriorate the rubber boot.

If you are concerned about the medium contact pressure of COP's then apply with a long q-tip to the ceramic area of the plug after installation of the plug but before COP installation.

Clean your sparkplug socket with brake cleaner before each plug installation to keep dirt and prior silicone contamination out of your COP spark tubes. HTH

 

Dielectric greases do not conduct... dielectric means insulator, so when you get right down to brass tacks and choose; a.) do you use a product that increases the resistance of the connection and prevents corrosion, or b.) use a product that improves the connection and prevents corrosion. I'm not making this up and opinions have nothing to do with it... it's physics pure and simple.

It's about best practices.

 

Ford's factory service manual specifically states the following when installing a COP:

Which is pretty much exactly as I stated above....

 

I'm not a huge fan of dielectric grease, however it is correct to use in a spark plug boot. The pressure is enough to ensure conductivity. And the voltage is high enough that the resistance (if any) is not an issue. The benefit of the dielectric grease sealing the tip contact area in the boot is very high.

It has to be dielectric or you will get bleeding of voltage outside the the plug down the body of the plug. You need an insulator.

Just a small amount does it.

If you had none, you could get corrosion on the contact point inside the boot, and it might be very difficult to remove the next time.

Don't worry about the resistance, it's not there in this instance.

Now low voltage wires (12 volt) and connectors around the truck is a different story. You need to keep it away or apply it after the connection is made to seal a connection, or it will cause some grief.

 

Wiki quote

"Another common use of dielectric grease is on the rubber mating surfaces or gaskets of multi-pin electrical connectors used in automotive and marine engines. The grease again acts as a lubricant and a sealant on the nonconductive mating surfaces of the connector. It is not recommended to be applied to the actual electrical conductive contacts of the connector because it could interfere with the electrical signals passing through the connector in cases where the contact pressure is very low. Products designed as electronic connector lubricants, on the other hand, should be applied to such connector contacts and can dramatically extend their useful life. Polyphenyl Ether, rather than silicone grease, is the active ingredient in some such connector lubricants."

Ideally, you would put a drop of the electrically conductive grease on the sparkplug's top tip and the insulating dielectric grease on the ceramic insulator of the sparkplug. You do not want the Polyphenyl Ether or any petroleum on the rubber boot because it will deteriorate the rubber. You also do not want a conducting element allowing voltage down the sparkplug tube as it will destroy the COP and an arc will split the rubber boot. You want to shield the insulator part of the plug to prevent contaminates from accessing your electrical connection and this is where you use the silicone and it also lubricates the rubber for later removal without destruction.

Put more simply you want your sparkplug boot to mimic the sparkplug in the same contact points. Insulator to insulator and conductor to conductor. HTH