circlex

Delete me.

Daniel Dudley

I have never used either of those, but you just need to use the thinnest coating of anti seize on a plug. Too much can cause major problems with the threads.

ammonman

The rule of thumb seems to be nickel based anti-seize for Fe-to-Al or Al-to-AL while the copper based stuff is reserved for Fe to Fe only. The copper base stuff will cause corrosion when in contact with Al.

Hope this helps.

Mike

GlenL

Really? I thought it was the copper for Al-to-Fe.

In any case, I use the plain silver Permatex on the plugs. Always come out easy. Make sure to torque to spec. The sealing rings make it feel funny, like you're not getting it completely tight but that's the way it is.

jthwan22

I use the silver stuff on spark plug with no problem. The only time I am careful is using it on O2 sensor. I was told the anti-seize can kill O2 sensor when it gets on the holey part.

Giovanni

Put the new plugs and torque them properly. You won't need anti-seize. Torque them too much and you will you either will wish you used anti-seize or you'll wonder why the anti-seize did not work. I never used anti-seize on plugs, use too much and it can make its way in the combustion chamber.

GlenL

Oh, oh, oh.

This is really poor advice.

Perhaps you change plugs every year or two. Once you've spent two hours praying that plug will come and a spark plug job won't turn into a head gasket job because it needs to come off, you'll anti-seize the plugs.

Mrmerlin

a small wipe with a brush of antiseize should be used on the plugs , it silly to not use it as you wont know the damage you have created till its time to replace the plugs.
Same goes for the wheel studs

Giovanni

Could it be that they were overtorqued and not because anti-seize was not applied?

blown 87

Gio, you are going to get bit if you do not use anti-seize on plugs.

Just make sure that it is not on the first three threads.

stolarzj

To throw a wrench in the thread, I recently read this in a 911 engine rebuilding book.

"Porsche doesn't recommend the use of anti-seize compund, as detailed in Porsche Techinal Bulletin 9102, Group 2, identifier 2870. The bulletin applies retroactively to all Porsche models and the theory is that the anti-seize tends to act as an electrical insulator between the plug and the cylinder head".

After reading that and doing some research I have found that spark plug manufacturers don't suggest the use of anti-seize as they have anti-seizing compounds built into the metals of modern day plugs that negates the need for anti-seize.

Mrmerlin

Stolarz thats a good point the other part thats not being mentioned is that there are lots of different spark plug makers and thus lots of different finishes that the threaded parts are made of.

GlenL

Good point. Here's a case:

I was working on an '85 928 last Summer and six plugs came out fine. They looked to have anti-seize on them. One was tough and one was nearly impossible. Those looked to have no anti-seize. Once broken loose they needed to be worked back-and-forth as I could feel them galling up.

I always did it before and this reinforced always doing it.

I don't put any goop under the washer or the plug bottom. That'll leave more than enough area to conduct the spark. Consider that the wire has a tiny cross-section. A spec of contact is good enough and the area between the plug bottom and the head is probably 100x the size.

Dave H.

copper on spark plugs.

silver on O2 sensors.

Mrmerlin

do not use copper its used for steel to steel .
the heads are aluminum