locked spark plug?

Hello...

Does anyone know a trick for getting a stuck spark plug out of an aluminum head....???

My wifes ride (and kids) is a 99' Chevy Venture with a 3400 V6

After spending about 6 hour changing the thermostat I thought I should change the plugs and wires

I got 5 of the 6 out but number 6 refuses to come out!

I can back it out 2 turns but no more (it gets tight) I can tighten it back in....I think it's galded?

I bought it at 50,000miles and someone put Bosch supers in it with no anti-seaze?

The plug is on the drivers side back and I had to drop the exhaust to get room to get at it.... I have tried it hot and cold and seams to make no difference...I used P/F and oil...no help either

I don't want to force it because bosch super plugs like to snap off behind the threads....

If I can't get it out....I will be forced to drop the engine (out the bottom) and drill and tap with a Heli-coil....

Any suggestions...???? Thanks Doc.

i'm sorry to say it but i have never had luck getting plugs out of aluminum heads once the threads get buggard. odds are you have a chunck of aluminum stuck in the threads of the plug and its stripping the threads on the head as you turn it out.

i would probably leave the plug in there and wait until it starts running bad on that cyl before i would drop the motor for a heli-coil. you may get 50k more miles before you notice it . thats just me though, i'm lazy :p

I am lazy too....but thats the cylinder popping the misfire codes (obdII) and it runs ok til about half throttle then it gets stupid...

I know I cracked the plug turning it in and out.....I'd hate to do it to the next guy but I thought about trading it in....