Old timer told me to stop using anti-seize on spark plugs in aluminum heads

He said I was asking for galling or overtorquing issues, so I switched to a dry torque spec with a slight grease on the threads only. Anyone else run into problems from too much anti-seize causing the plugs to back out?

2 comments

2 Comments

grantthomas2d agoTop Commenter

Wait, did your old timer mention anything about the type of anti-seize you were using? The silver copper stuff conducts electricity way differently than the nickel based stuff, and I've seen that cause issues with spark plug readings on modern coil-on-plug systems. He's right about the galling risk though, especially on aluminum heads that have already been heat cycled a few times. The main thing people miss is that anti-seize changes the friction coefficient enough that you can actually hit the same clamping force with less turning force, which messes with the torque wrench reading. I've been using a tiny dab of nickel antiseize on just the first couple threads and torquing to the middle of the dry spec range, never had one back out or seize up in twenty years of wrenching.

umab352d ago

The silver copper stuff is a nightmare for coil-on-plug systems, I've seen it cause misfires that had people chasing their tails for weeks. The nickel based stuff is all I'll touch now, exactly like you said, just a tiny dab on the first couple threads and that's it. The friction coefficient thing is huge and barely anyone talks about it, you're dead on there. I've had guys swear their torque wrench is broken just because they didn't account for how anti-seize changes the feel. What gets me is people slathering it on like toothpaste, thinking more is better when really it just makes a mess and throws your torque off. Your method of going to the middle of the dry spec is exactly what I do now, took me a few seized plugs on an old Ford to learn that lesson.