anti seize on spark plugs

[The motor guy]

what's your opinion on this? A quick search on the internet says pretty much all manufacturers recommend against it. I changed the plugs on my boat today and I couldn't get them out with a regular 3/8" ratchet. It took a 2ft long breaker bar to crack them loose and you sure heard the crack when they broke loose. I think the spec was like 20 ft lbs. I just put them back in with my 3/8" ratchet and gave it one small grunt and called it good. There were no crush washers on these, so they pretty much stopped turning immediately once seated. I want to be able to get them out the next time, so saw no need for 20 ft lbs or whatever the torque rating was.

 

[Nukeman7]

Use the search feature to retrieve previous BITOG threads on this subject. There have been several posted recently, so another one would be redundant.

https://bobistheoilguy.com/forums/threads/anti-seize-not-good-to-use.383893/

https://bobistheoilguy.com/forums/t...-spark-plugs-in-aluminum-honda-engine.383156/

https://bobistheoilguy.com/forums/threads/honda-odyssey-plug-change-interval.384695/#post-6937792

 

[spasm3]

Use the search feature to retrieve previous BITOG threads on this subject. There have been several posted recently, so another one would be redundant.

https://bobistheoilguy.com/forums/threads/anti-seize-not-good-to-use.383893/

https://bobistheoilguy.com/forums/t...-spark-plugs-in-aluminum-honda-engine.383156/

https://bobistheoilguy.com/forums/threads/honda-odyssey-plug-change-interval.384695/#post-6937792

Ohhhh you beat @kschachn to it!

 

[doitmyself]

what's your opinion on this? A quick search on the internet says pretty much all manufacturers recommend against it. I changed the plugs on my boat today and I couldn't get them out with a regular 3/8" ratchet. It took a 2ft long breaker bar to crack them loose and you sure heard the crack when they broke loose. I think the spec was like 20 ft lbs. I just put them back in with my 3/8" ratchet and gave it one small grunt and called it good. There were no crush washers on these, so they pretty much stopped turning immediately once seated. I want to be able to get them out the next time, so saw no need for 20 ft lbs or whatever the torque rating was.

20 ft. lbs. is not very much. Too loose can create problems also.

 

[The motor guy]

20 ft. lbs. is not very much. Too loose can create problems also.

I guess these are called tapered seat plugs. Looks like finger tight then. 1/8" more of a turn with a ratchet after that. Some people said 10ftIbs

 

[KevinMalone]

If you must use it, be sure to adjust your torque target to account for the decreased friction

 

[vavavroom]

I'm pretty sure most modern spark plugs have threads that are plated with an anti-corrosion substance. I don't think anti-seize is advisable unless specified by the spark plug manufacturer. As far as torque goes, I shoot for the lower end to mid-range of the specified torque or finger-tight plus a 1/2 turn.

 

[billt460]

Seeing as plugs in these newer engines have much more thread length, (up to and over an inch), and are screwed into Aluminum heads, where they usually remain for 100,000 miles or more, I would definitely use anti seize.

 

[Lubener]

what's your opinion on this? A quick search on the internet says pretty much all manufacturers recommend against it. I changed the plugs on my boat today and I couldn't get them out with a regular 3/8" ratchet. It took a 2ft long breaker bar to crack them loose and you sure heard the crack when they broke loose. I think the spec was like 20 ft lbs. I just put them back in with my 3/8" ratchet and gave it one small grunt and called it good. There were no crush washers on these, so they pretty much stopped turning immediately once seated. I want to be able to get them out the next time, so saw no need for 20 ft lbs or whatever the torque rating was.

That's tight enough for a tapered plug. No antiseize.

 

[hrv]

what's your opinion on this? A quick search on the internet says pretty much all manufacturers recommend against it. I changed the plugs on my boat today and I couldn't get them out with a regular 3/8" ratchet. It took a 2ft long breaker bar to crack them loose and you sure heard the crack when they broke loose. I think the spec was like 20 ft lbs. I just put them back in with my 3/8" ratchet and gave it one small grunt and called it good. There were no crush washers on these, so they pretty much stopped turning immediately once seated. I want to be able to get them out the next time, so saw no need for 20 ft lbs or whatever the torque rating was.

This has been talked about at least a zillion times on this site...do a search...

 

[Mackelroy]

No I would never used antiseize on a spark plug for fear of entering the cylinder, but a tiny(unseen) film of dielectric grease, Ive used

 

[72C10]

I try to inspect mine once a year so I don't find it neccessary.

 

[TomYoung]

No I would never used antiseize on a spark plug for fear of entering the cylinder, but a tiny(unseen) film of dielectric grease, Ive used

Dielectric grease is an insulator, so that’s a very, very, terrible, horrendous idea.

 

[TomYoung]

I try to inspect mine once a year so I don't find it neccessary.

That’s excessive, and increases the chances of an overtightening, cross thread, or cracked insulator/broken plug event. Plugs should be installed and replaced on schedule. Only take them out if you need to diagnose something, or when it’s time to replace. Btw, my suggestion is to replace them when they come out if you have more than 25,000 miles.

 

[KrisZ]

How many BITOG threads does it take to put antiseize on a spark plug?

This much…

 

[kschachn]

Dielectric grease is an insulator, so that’s a very, very, terrible, horrendous idea.

No it's not. Electrical connection does not occur between the thread spaces. If not the grease then air is there and that's an effective dielectric.

This is a common misconception that is often repeated here.

 

[SC Maintenance]

No it's not. Electrical connection does not occur between the thread spaces. If not the grease then air is there and that's an effective dielectric.

This is a common misconception that is often repeated here.

Its an insulator, or at best case its "non-conductive" if you want to get really technical, so its not something I would want to put on threads of something I needed to ground.

In traditional thread fashion:

https://mgchemicals.com/blog/dielectric-grease-on-spark-plugs/

https://www.motortrend.com/how-to/w...tric grease?,and doesn't conduct electricity.

https://www.vfrdiscussion.com/index.php?/forums/topic/98853-dielectic-grease-the-pros-and-cons/

https://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm

 

[kschachn]

Yes it is an insulator. I am not arguing that it is not. But air is too. If the threads are not making metal-to-metal contact for conduction (just like in every other termination) then there's always a dielectric in the interstitial space. People get all stirred up on the grease when they do not understand how electricity is conducted in a terminal joint.

What I was referring to with my "No it's not" statement was the poster's "that’s a very, very, terrible, horrendous idea". Sorry that was unclear. What is actually a very bad idea is to use an electrically conductive grease in an application such as this.

 

[TomYoung]

No it's not. Electrical connection does not occur between the thread spaces. If not the grease then air is there and that's an effective dielectric.

This is a common misconception that is often repeated here.

Help me out here. The ground electrode is attached to the threaded metal part of the plug, and the current flows from there to the engine head and so on.

 

[KrisZ]

The insulator argument just shows that people don’t know how a threaded interface works.

There is always a gap and a section that makes full metal to metal contact.