Why would #7 spark plug keep backing out?

[85_SS_302_Coupe]

OK, i dont have aluminum heads, they're stock E5s, with stock equivelent Autolite plugs and Motorsport 8mm stock replacement wires. I'm in the process of just doing a tune up, but untill then i'd like to figure out if there's some other problem that's causing this.

It's backed out 2 times in the last 10 or so times i've driven the car, causing a pinging/ticking noice that sounds like my motor is about to fall apart (which takes about 3 years off my life each time i hear it)

I'm not tightening it by torque specs or anything like that, and i'm not tightening it any less than the other 7 plugs, so why just this one plug?

 

[kdog_x]

I had a similar problem with mine. The threads on either the head or the spark plug are probably stripped -- they strip fairly easily on the plugs. You could try another plug to see if it's the head or not.

There's also a quick fix. Just wrap a bunch of teflon tape around the threads and it should stay put.

 

[85_SS_302_Coupe]

"see honey, the threads on my head are stripped...THAT'S why i need these AFR 165s"

Oh man i can see it now...lol


I asked my local speed shop guy and he pretty much said the same thing, i just thought maybe someone here might have experience with it. He told me a nice set of aluminum heads would solve my problem...i said yea and they'd solve a couple of your money problems too huh?