Use of dielectric grease - spark plugs

[TheV6Bird]

I just changed my friends 98 Jeep Grand Cherokee I6 spark plugs and wires.

This was the first time I ever changed spark plugs and wires on any car, EVER! I knew what to do from reading and watching my brother change his plugs: dielectric grease on the ceramice part, anti-seize on the plug threads, dielectric grease on the top of the boot that plugs into the distributor.

After starting it up, the car ran really rough! Five minutes later, I realized I crossed one of the wires on top of the distributor cap. Switched that out, and it ran perfect.

Now he calls me and says the car is running rough like before. I started thinking that the only way this could happen is if the plug popped out of the distributor. Was I not supposed to use dielectric grease on the top part of the boot? The tops of the boots didn't feel that snug in the distributor cap.

[grayman]

Re: Use of dielectric grease - spark plugs

i don;t grease the boots on the distributor. it does not get real hot there....not like spark plug end.

you don't need much on the ceramicpart of plugs either. just a dab is fine.

[TheV6Bird]

Re: Use of dielectric grease - spark plugs

OK I thought you NEEDED grease on the boots...apparently, the grease is making the boots easy to move around, the a few of the boots are popping off of the cap just enough to make the engine be rough.

I'm gonna swab the inside of the boots with Q-tips to get as much grease out of there as I can today.

[zlexiss]

Re: Use of dielectric grease - spark plugs

I grease both ends, just helps them come off after baking underhood for years. Yeah, but just a thin film is fine.

I'd just make sure nothing's popped off and no wires are arcing or otherwise misrouted.

[FunkZ]

Re: Use of dielectric grease - spark plugs

Grease 'em up! The metal clip inside the boot should hold the wire in place. If one popped off either it's defective or it wasn't snapped on quite all the way.

[Rob Bell]

Re: Use of dielectric grease - spark plugs

I agree, the grease should not make it pop off. Either you did not seat them all the way, or the clips may be worn so thay not providing enough clamping force. You may be able to squeeze them to make them tighter, or else maybe new wires are needed.

[bah]

Re: Use of dielectric grease - spark plugs

isnt dielectric grease nonconductive?

[Rob Bell]

Re: Use of dielectric grease - spark plugs

No, it's made specifically to be conductive and to still allow you to get parts apart and to prevent corrosion.

[bah]

Re: Use of dielectric grease - spark plugs

i must be thinking of something else then, i thought it was odd for you to be coating your spark plugs in something that is nonconductive, lol

[zlexiss]

Re: Use of dielectric grease - spark plugs

Dieletric grease is non-conductive. Otherwise it would cause arcing down the porcelin plug insulator tower towards the engine block.

There's enough metal-to-metal contact through the grease to take care of the circuit path. The grease just prevents corrosion.

[Rob Bell]

Re: Use of dielectric grease - spark plugs

I stand corrected, zlexiss is right. It IS non-conductive. Ya learn something new every day. i just assumed it was conductive because you use it on electrical connections. I guess that's what happens when we assume things, eh? :)

[bah]

Re: Use of dielectric grease - spark plugs

thats what i thought, i figured i might just be going insane maybe, the world may never know :(