: Anti-Sieze and Spark Plugs



getaway6819
07-11-06, 07:47 PM
I find it intresting that the subject of using Anti-sieze compound on spark plug threads was not found in a search of this forum. I also belong to the Jag-Lovers.org since I have two Jaguars a V12 XJS and a Vanden Plas. There are numerous posts there about using anti-Sieze compound on plug threads. The plugs being steel and the heads being aluminum and the corrosion problems when two metals one of which is less noble than the other are put together. I was just wondering if these problems are much less with cadillacs.
Does any one use anti-sieze? If not then why not?

Mike O

JimD
07-11-06, 08:50 PM
I do not use an aftermarket thread product on new ACDelco (recommended part) sparking bolt threads because ACDelco has agreed to treat the threads of the recommended replacement part per Cadillac powertrain engineering specifications.

Not to mention the possibility of scewing the recommended torque value reading.

Ranger
07-11-06, 08:52 PM
Our old Guru had always advised against it. One reason being that it will cause you to over torque them. The other being that it can cause carbon traking if not used carefully and sparingly. The plugs came out very easy on my '97 at about 90K so I did not bother using it.

getaway6819
07-12-06, 04:24 PM
I do not use an aftermarket thread product on new ACDelco (recommended part) sparking bolt threads because ACDelco has agreed to treat the threads of the recommended replacement part per Cadillac powertrain engineering specifications.

Not to mention the possibility of scewing the recommended torque value reading.


Jim,
Please explain what Ac Delco agreement and threag treatment means to me. Forgive me but I do not understand that part of your answer.
What exactly is the correct torque value when tightening the plugs. I have seen no mention of how many FT Lbs to tighten the plugs.
Thank You
Mike OConnor

Night Wolf
07-12-06, 04:45 PM
well, the 4.9 has cast iron heads....

I never heard of the dissimilar metal theory, tho I suppose its true...

it prevents the plug from geting stuck in the block due to excess heat... I've seen that happen a few times. I use it on all of my cars and any time i do a spark plug job.

Caddyshack100
07-12-06, 09:08 PM
I use anti-seize religiously on my spark plugs, I have never seen any treatments on spark plugs, even on the replacements that I changed on my 98 Deville at 100K. GM and for that matter most other OEM's use treated threads on O2 sensors.

Ranger
07-12-06, 11:02 PM
Getaway,
I am not sure but I would venture a guess that the threads are zinc plated or something like that to prevent or reduce corrosion.

Night Wolf,
Dissimilar metals when in contact with each other will have an galvanic action causing corrsion. This link may explaine it better than I can.
http://www.galvanizeit.org/showContent,173,215.cfm

eldorado1
07-12-06, 11:16 PM
Going by the "book", antiseize is not needed.

Going by experience, antiseize is needed.

I have never had any problem with plugs getting stuck when antiseize was used. However, in another car of mine that had aluminum heads.. I got all the plugs out but one. It welded itself in, and there was no chance of getting it out without stripping the threads or shearing it off. So I left it.

ewill3rd
07-13-06, 01:29 PM
I use it on some engines I know I have seen trouble with, not on others that I have never seen problems on.
It CAN cause problems, but it CAN eliminate problems.

GM makes some special stuff for O2 sensors that costs about 40 bucks a can, I used to make my service manager buy one and I used it to reinstall O2 sensors and some spark plugs, mostly on aluminum heads. I don't recall it ever being an issue on cast iron heads.

It's been a while since I had a can of that, I don't remember the part number.
It's awesome stuff though.
You let it dry before you install it, but don't leave the cap off the can or you'll ruin it!

denscor
07-13-06, 10:48 PM
From what I seen and heard it will also cause a miss fire! I know on the vette if I use them it miss fire and guys on the Forced Air Forum all have the same trouble if they use anti seize.

C170B
07-13-06, 11:56 PM
Non automotive comment

Spark Plug Thread gasket compound is used frequently on piston engine aircraft engines. Many alum cyl heads have been helicoil because of thread problems. After the repair sometimes the entire helicoil will back out due to stuck sparkplug. The thread compound is supplied by the PLUG mfg so it must be important. I hear that the special ingredient is MICA in suspension. It prevents the plug from welding up and I suspect that A/C owners end up using it on their cars and lawnmowers.

ewill3rd
07-14-06, 07:22 AM
If you use the wrong kind I could see it causing a misfire, also if you are not careful and you get it all over the tip of the plug... I can see that too.

Patrick7997
07-14-06, 11:20 AM
I used a teeny little bit of anti-sieze on my plugs at the last change.... no ill effects. The ones on the back side of the Northstar were really stuck, so I decided to do that.....

Correct plug torque is 15 foot pounds, I believe.

parts68
07-16-06, 08:57 AM
small amount on the threads only
start about 2 or 3 threads from end and
end it before end of thread
being sloppy is what causes misfires
remember alittle goes a long way especially when you get it on your face.

JohnnyO
07-16-06, 09:26 PM
I think that especially with aluminum heads you should use it. Back in the day when changing plugs was an annual thing (or more) it wasn't a big deal but with the so-called 100,000 mile plugs you can strip the threads out of the aluminum.

dkozloski
07-16-06, 10:12 PM
All aircraft engines made in the last 50+ years come from the factory with stainless steel helicoil inserts 100%. Mechanics sometimes use anti-seize compound but the factories specify the use of plain engine oil. This info does not transfer to autos because they don't use stainless thread inserts. For aluminum heads, use a zinc based anti-seize such as Permatex. Use very sparingly and keep it away from the sparkplug electrodes. Use a wire wheel mounted on a bench grinder to clean the threads on the plugs to make sure there is no carbon buildup. If you clean the plugs with a grit blaster make sure you get all the crap out clear down in the plug.