QUOTE(DBCooper @ Nov 1 2012, 05:03 AM)
It could be some carbon in the threads near the chamber. There isn't much alternative to just working the carbon off, screwing the plug out till it binds, then in a half turn or so, then back out, trying to clean a little at a time. It might work, but that's best case. Worst case is that you already have stripped threads and your plug is now trying to cut some new threads in your head. How are the other plugs, similar, or is it just this one? If you have stripped threads again not much alternative, it's already happened, so you can just remove the plug the same way, out a bit, in some, then out again. If they're stripped you'll see aluminum in the threads once the plug's out, and you'll need a heli-coil installed in that plug hole. Don't try to tighten the plug and drive the car, the motor will just spit it out after a while.
all plugs come out normaly except #1.
#1 comes out about 2 turns then binds.
I can fully seat it after it binds.