removed stuck spark plug - cln oil on head threads ?

[BobbyC777]

Very interesting about the 30% torque reduction with anti-seize - that's a lot!

[cn90]

I have used anti-seize and 18 ft*lb for so many cars, BMW, Volvo etc. Zero issues.

I posted this topic on bimmerfest, in fact, it took > 110 ft*lb to damage the cylinder head threads...So 18 ft*lb is Ok, even with anti-seize.

[Blacklab467]

Note that the purpose of a given torque on spark plugs is twofold; first to secure the spark plug in place and second more importantly, to get the malleable metal to seal the plug to the head. In fact an aluminum head will tolerate much higher torque than the specified value without damaging the threads.
I replaced the original spark plugs on my car at 240,000 kms and they came out with such difficulty that I thought I ruined 4 out of 5 threaded bores, mostly due to carbon buildup on the plug threads that extended into the CC. I always use anti-seize on spark plugs because I don't want to turn an hour long job into a twelve hour job.

[erikv11]

...I replaced the original spark plugs on my car at 240,000 kms and they came out with such difficulty that I thought I ruined 4 out of 5 threaded bores, mostly due to carbon buildup on the plug threads that extended into the CC. I always use anti-seize on spark plugs because I don't want to turn an hour long job into a twelve hour job.

Yeah, if the plugs will be left in a ridiculously long interval (240k km) then it is worth just cracking them loose every couple years, to avoid letting the threads accumulate too much detritus. You can use the removal as an excuse to see how they are wearing. Of course, whatever you put in next is on your watch, so presumably won't go for 240k km this time ...

[MoVolvos]

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NGK doesn't require or recommend anti-seize due to their metallurgy design.

https://ngksparkplugs.com/en/resources/ ... park-plugs
.

[abscate]

Don’t sweat any oil, kroil, or PB that gets into cylinder. To quote a famous biologist on this forum,

“. it’s an engine, not a neuron…”

[firstv70volvo]

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NGK doesn't require or recommend anti-seize due to their metallurgy design.

https://ngksparkplugs.com/en/resources/ ... park-plugs
.

This is different advice from NGK than previously and I can only think it's because too many people overtighten the plugs or use too much of it when using anti-seize grease. The metallurgy of the plugs may not need the anti-seize but the aluminum threads in the cylinder head do benefit from anti-seize grease preventing potential corrosion and galling.

[MoVolvos]

.
NGK doesn't require or recommend anti-seize due to their metallurgy design.

https://ngksparkplugs.com/en/resources/ ... park-plugs
.

This is different advice from NGK than previously and I can only think it's because too many people overtighten the plugs or use too much of it when using anti-seize grease. The metallurgy of the plugs may not need the anti-seize but the aluminum threads in the cylinder head do benefit from anti-seize grease preventing potential corrosion and galling.

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The oxidation and galling are probably from plugs with metal that would cause those issues with aluminum, whereas the NGK won't. That's a huge liability and class-action if the science behind their product was not in fact true and documented.
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[abscate]

I stick with copper plugs since they come out every 20-30k and dont get galled

I use Aluminum antiseize on the threads I don’t use a torque wrench here. Torque isn’t critical. Gasket compressed, then1/4 turn

If I’m going to the trouble of cracking them to fight seizure, new ones are going in. Especially since they are FreeCP.

[BobbyC777]

FreeCP? I'll bite.