Old timer told me to never use spark plug anti-seize on modern engines

My mentor from the 80s swore by anti-seize on every spark plug, said it saved him from seized heads a dozen times. Then a customer brought in a 2017 F-150 with misfires, and I found the plugs were over-torqued from the lube causing false readings. Turns out Ford and Toyota both say to install them dry now. Who do you trust, the old school mechanic or the service manual?

2 comments

2 Comments

the_vera1d ago

That's the thing though - the torque specs in the manual assume dry threads. When you add anti-seize, the friction changes and you end up cranking it way tighter than you think. I've seen techs snap plugs off in aluminum heads because they torqued to spec with lube on there. The manufacturers test this stuff in labs, so I'd lean toward the manual on this one.

walker.alex23h ago

The manufacturers test this stuff in labs" yeah and they also test it in perfect conditions with brand new parts every time lol. Real world is different, aluminum heads get corrosion no matter what the manual says. I've pulled plugs out of 200k mile Toyotas that had anti-seize and they came out smooth, while dry ones I've seen get stuck so bad you're drilling them out. The torque issue is real though, you just gotta back off the spec by like 10-15 percent when you use lube. Old school guys might not have fancy torque wrenches but they know what a snug fit feels like from experience.