Any recommendations on thread lubricant for spark plugs?

[WhiteDiamond]

I just pulled my OEM plugs, dealer changed at the Audi service interval(1st change) and now at 76,xxx miles due to my blown turbos. Have the RS7 plugs ready to go in. 6 of the 8 plugs needed a good soaking to prevent, in my opinion, damage to the threads. I started to feel them bind a bit on removal, so soaked them and worked them slowly out. I see the OEM recommends nothing, but just curious if any of you are using something on the threads.

[gk1]

Good question.
I have seen pro mechanics use antiseize, but I believe as you saw too that nothing is recommended. NGK also does not recommend anything.
The antiseize will change the torque reading and the NGK spark plugs threads themselves should be finished with an anti-corrosive coating.
https://ngksparkplugs.com/en/resourc...ut-spark-plugs

Personally I would not use anything and I would very carefully clean the threads as best I could with a thread chaser if it will fit.

https://www.amazon.com/Lisle-20200-T.../dp/B0009OMYCO

[MSq5]

I'd be very reluctant to use anti-seize compound on spark plug threads. It might impede heat transfer from the plug to the cylinder head which serves as a heat sink to pull heat away from the plug.

There is special high temp, high nickel content anti-seize that is supposed to not interfere with heat transfer, and made for spark plugs. Even then, the lubricity might cause over torquing and thread stretch.

[xander3zero]

I've used plain anti-seize several times over the past 5-6 years since I've done my own plugs... Never had a problem.

Yes it will technically cause less preload to be developed in the threaded region with the same torque value - but I've never heard of a spark plugs 'backing out'.

If you're worried about that then add 2-3 ft-lbs more torque or go online and use a torque calculator using 0.20 as the "K" friction coefficient (0.20 commonly used for lubricated/anti seized threads).

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[WhiteDiamond]

I can see the threads on the plugs have some sort of coating or treatment done to them. NGK has a name for the coating.

I have NGK plugs in my "project" car that I have always used anti-seize on the threads. Never an issue.

GK1, thank you for that link. I do not think I have ever seen one of those. I have only cleaned threads with taps in the past and I am very reluctant to do such a thing in this case. Also, don't want any metals going down into the bore. Going to do some research on those. Want to button the plugs up today, but the plugs are supposed to move to a 10 to 15K mile interval on Stage III. I'll probably do the first change in that window and see how the plugs look. Modify the range from there and have one of those thread cleaners here.

[Alabama]

Good question.
NGK also does not recommend anything.

Not only NGK at the high end, but also Autolite, AC/Delco, and Champion specifically recommend to not use anti seize; Bosch says none needed. Only Denso seems to accept the use of anti seize but also says to always follow the recommendation of the engine manufacturer, not the spark plug manufacturer. The thread chaser suggestion is slick! But, won't debris drop down into the cylinder? Not to worry?

[WhiteDiamond]

Not only NGK at the high end, but also Autolite, AC/Delco, and Champion specifically recommend to not use anti seize; Bosch says none needed. Only Denso seems to accept the use of anti seize but also says to always follow the recommendation of the engine manufacturer, not the spark plug manufacturer. The thread chaser suggestion is slick! But, won't debris drop down into the cylinder? Not to worry?

From the research I did after his reply, it shouldn't be an issue if only using it to clean the threads. Not to be used on damaged threads. The tool is not meant to cut metal, but only clean the existing threads of build up from whatever has seeped into them during the usage time. There are some out there that recommend putting a heavy grease in that channel to catch any debris, but some don't believe that works.

[daytona rs7]

another vote that regular anti-seize is ok.
iv used it on about 6 different cars ive owned. never had a spark issue.

[mrdouble99]

never put never seized on a sparkplug, never.

modern plug have a plated anti-seized coating already, so if you put never seized you are going to over torque them and next time you remove them they will be seized for sure

[xander3zero]

never put never seized on a sparkplug, never.

modern plug have a plated anti-seized coating already, so if you put never seized you are going to over torque them and next time you remove them they will be seized for sure

If the threads have an anti-seize coating then they are already "lubricated" and adding a small amount of anti-seize should not change the friction coefficient enough to cause severe over-torquing.

Let's remember that were replying to the OPs post about how his plug threads were seized/corroded...

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[WhiteDiamond]

The plugs I removed from the car are the newer Audi spec RS7 style NGKs. According to NGK, these plugs have a special coating on the threads, yet mine felt very poor on several of the plugs during removal. They were very close to the Audi service interval milage, but still under it. Since I am going Stage III on this, the plugs will come back out in 10K miles so I can get a feel for how it is running.