Anti seize on spark plugs?

[03GMCYukonXL]

So I recently had a stuck spark plug in cylinder number 8. As you all know, that's a difficult one on the best days. Anyways, it was so stuck that the nut part broke off and I couldn't get an extraction tool in there. So, I removed the head. The small extraction tool wasn't cutting it so I bought a larger one.... This plug was so stuck that it's a permanent part of the head now. The extractor tool dug all the way to the other side and cracked my head. I've since bought a new head. I was told this happens because I didn't put anti seize in the plugs, however, the ngk recommendations say to install them dry, as anti seize may affect the torque settings (I never torque them, I just do hand tight and then a snug pull).

And yes, I soaked for 2 days in wd40, pb blaster, and an acetone/transmission fluid mixture. I also tried the female style extractor first.

 

[mikez71]

I've seen instructions like that, but I have to wonder how much it's really going to affect torque, especially at the relatively low torque/angles recommended..
I wasn't big on anti-seize for sparkplugs, because I've never had an issue. But after seeing yours, I might reconsider!

 

[RoadTrip]

I’ve used it for years on my steel head engines and used the higher temp copper anti-seize.

I haven’t used it with any of my aluminum head engines because I haven’t made the time to research if there is a chemical reaction with the aluminum.

 

[OR VietVet]

I have used anti seize, the silver/grey stuff, for close to 35 years now, with no problems at all. I have never used a torque wrench on a spark plug because I know how to hold my tongue, in my teeth, just right.

 

[mikez71]

Silver-grey stuff crayon here too..
If anything it will drag, not lubricate, causing you to under-torque..
So I should have said 'at the relatively AMPLE torque required'

I guess undertorque could occur due to instructions of 'finger tight' & 'additional 1/16 turn'...
Finger tight might not be bottomed out with gooey threads..

Seems manufacturers really like torque angle on the tapered seat.. and only spec torque setting on gasket seats..I never bothered to read those instructions..
I expect to feel 15-25 foot pounds regardless of plug type..
No ugga-dugga, just ug..

Didn't by chance torque that plug on a hot engine?
Seems most unlikely with rear plug locations due to access..

At least you powered through and got it done, pat yourself on the back...
I'd have been swearing for days on here before I got done!

 

[Sir_Hiro]

I’ve used it for years on my steel head engines and used the higher temp copper anti-seize.

I haven’t used it with any of my aluminum head engines because I haven’t made the time to research if there is a chemical reaction with the aluminum.

I've used it on my Alum Head 383 per Blueprint. I just used the silver speed stick. No issues yet but its only been 2 years.

I havent done it with the yukon yet because I havent gotten around to doing the plugs but I will also be using the Speed Stick. My rule of thumb is tight then hmph tighter

 

[03GMCYukonXL]

Yeah I've personally never used it. I've never had this happen. If you look in the pic you can still see the tip of the spark plug that the extractor bent upwards. There is not getting it out.

 

[03GMCYukonXL]

I have used anti seize, the silver/grey stuff, for close to 35 years now, with no problems at all. I have never used a torque wrench on a spark plug because I know how to hold my tongue, in my teeth, just right.

What is the "silver/grey stuff"? I'd love to try it out.

 

[Sir_Hiro]

This is what I use.

 

[B-train]

Good information, never thought of using it on spark plugs. I've always used a light brush of oil off a fingertip on the threads and then use the same torque method as @OR VietVet .LOL

I've never had a GM plug that wouldn't come out, but it's good reminder to always guage how they react when going to remove them. I know the Ford modular V8's would probably benefit from this - many horror stories from fellow technicians about them.

 

[donjetman]

I always use some sort of lube on spark plugs in aluminum heads.
I never have used a torque wrench for spark plugs. I just snug em up, not overly tight. Never had a problem.

 

[OR VietVet]

Permatex Anti-Seize #80078. I have had the same bottle of anti-seize for close to 10 years. Has a brush on a stem under the cap.

I have never had problems with my own plugs removal. But since I work out of my garage, I have run in to "too tight" plugs before. The Ford's that have the plugs up top have water that drips down from above off the cowling and causes problems.

 

[Sir_Hiro]

This is why I went to the roll on stick anit seize lol

 

[SpareParts]

This is what i use in a lot of places including spark plugs. Got two cans free from work because it was expired. Almost everything at the ole aircraft factory has a 1 year or less shelf life.

 

[LSCALADE]

Hope this helps.

Most modern spark plugs (ACDelco, NGK, Denso, Bosch, etc.) come with:

• Nickel-plated or zinc-coated threads
• Designed specifically to prevent galling and corrosion in aluminum heads

Manufacturers generally recommend installing them dry.


Why anti-seize can actually cause problems....

1. Over-torque risk
   Anti-seize acts as a lubricant.
   That means the torque wrench reading becomes inaccurate.
   ➜ You can easily over-tighten the plug, stretching threads in the aluminum head.
   ➜ In worst cases: stripped threads.
2. Heat transfer issues
   Spark plugs rely on proper torque for correct heat transfer to the cylinder head.
   Excess anti-seize can slightly alter that interface.
3. Modern coatings make it unnecessary
   The plating already prevents seizing.

What manufacturers say

• NGK: Do not use anti-seize unless specifically required.
• Denso: Install dry.
• ACDelco: Install dry unless otherwise specified.
• Ford & GM service manuals: Install dry on coated plugs.

When would you use anti-seize?

Rare cases:

• Very old engines with non-coated plugs
• Marine applications
• Engines exposed to extreme corrosion
• If a service manual explicitly calls for it

If used:

• Apply a very small amount
• Reduce torque spec by ~10–20%

 

[OR VietVet]

I do not "coat" the threads. I use a thin dab, not a glob, down near the end of the threads and as the plug is threaded in, the rear threads get a very light coating.

 

[SpareParts]

Hope this helps.

Most modern spark plugs (ACDelco, NGK, Denso, Bosch, etc.) come with:

• Nickel-plated or zinc-coated threads
• Designed specifically to prevent galling and corrosion in aluminum heads

Manufacturers generally recommend installing them dry.


Why anti-seize can actually cause problems....

1. Over-torque risk
   Anti-seize acts as a lubricant.
   That means the torque wrench reading becomes inaccurate.
   ➜ You can easily over-tighten the plug, stretching threads in the aluminum head.
   ➜ In worst cases: stripped threads.
2. Heat transfer issues
   Spark plugs rely on proper torque for correct heat transfer to the cylinder head.
   Excess anti-seize can slightly alter that interface.
3. Modern coatings make it unnecessary
   The plating already prevents seizing.

What manufacturers say

• NGK: Do not use anti-seize unless specifically required.
• Denso: Install dry.
• ACDelco: Install dry unless otherwise specified.
• Ford & GM service manuals: Install dry on coated plugs.

When would you use anti-seize?

Rare cases:

• Very old engines with non-coated plugs
• Marine applications
• Engines exposed to extreme corrosion
• If a service manual explicitly calls for it

If used:

• Apply a very small amount
• Reduce torque spec by ~10–20%

After dealing with seized plugs on a 2011 Toyota i don't care what the manufacturers say. Plugs are getting a very small amount of anti seize.

 

[LSCALADE]

I have never used a torque wrench on spark plugs, an old mechanic once told me the trick to seating them. When you thread them in at some point you will make contact with the crush washer, rotational resistance will go up slightly for about 1 revolution until the crush washer is "Crushed" and at that point just a nice snug and you are good to go. Never had spark plugs come loose on me. I have however seen "torqued" spark plugs sitting there loose and upon tightening the crush washer was not seated all the way.

 

[03GMCYukonXL]

SpareParts​

Yeah this is my sentiment exactly. This is the first time I've had it happen this extreme and I don't want to ever have to deal with it again. Removing a head to get a plug out is crazy enough....but now replacing a head....I no longer care what the manufacturer says. It's getting some.

And yeah that's the exact thing I read long ago so I didn't use lubricant. I've learned the hard way lol.

 

[B-train]

This is SO true. My brother and I joke about this anytime we have to work with it. LOL

View attachment 478824
This is why I went to the roll on stick anit seize lol