socal57chevy

Plug threads are 14mm. Lisle makes a nice thread chaser socket that fits inside the spark plug well.


Also, never ever ever ever use anti-seize on spark plugs...EVER. Lubricant changes the torque values and spark plug torque is always a dry torque specification. Wanna overtighten something?...lubricate the threads. Please don't ever lubricate spark plug threads.

Coosawjack

None....they all had 4V heads but the '03's had the 3 thread plug bosses!!

A friend had a Mountaineer that had 3V heads and broke 3 plugs changing them......what a mess!!

redass02gt

I wonder if that contirbutes to the amount of spark plug issues. It's pretty common for people to use anti-seize without even thinking about it.

socal57chevy

I can't even count the number of wheel studs I've replaced because of the stuff. It has it's place, but is way overused. There's a pocket reference that has standard fastener wet torque specifications, and a plethora of other useful information, that I keep in my tool box. If I feel the need to use anti-seize on a bolt/nut, I pull out the book and adjust my torque wrench accordingly. Not enough people torque spark plugs these days. Most aluminum heads want the plug torqued to between 14 and 20 ft/lb. You just can't get that specific tightening them by feel. I honestly think that has more to do with it than the use of anti-seize, although I have repaired some blown out holes where anti-seize was used.
My advice for spark plugs:
1) Use a thread chaser to clean up the threads in the head. (not a tap)
2) Install the spark plug dry. (no oil or anti-seize)
3) Always use a torque wrench. (especially applicable for Nissan/Infiniti factory indexed plugs)

WJL

Hmmm, 12 ft/lb is 12 ft/lb wet or dry there are more pluses to using anti-seize, it helps with dissimilar metals and prevent corrosion.

In most structural applications most fasteners are pre-lubed, APR thinks so too

not to argue but i completely disagree