I'm new here so I searched as best I could and did not find my topic; so here is another question.

Three spark Plugs came out without a problem. One will turn about an eighth of a turn and that's all. I've let some Kroil nut buster, soak in and increased the turn to maybe a quarter of a turn.

Do I need to remove the head and plan on repairing with a Heli-coil?

Thanks

 

What motor?

 

The spark plug is seized due to neglect. Good luck getting out w/o breaking it.

 

96 Civic - 4 cyl - neglect is a nice way of saying it.

 

Something that I have done to remedy this situation is to start the car for about 5 minutes then remove the plug. Then let the car cool down completely to ambient temperature before putting the new plug in otherwise there is a good chance it will seize

 

Mmmm - I like that idea. If that fails I can at least run it a while til I have time to pull the head.

 

Loosen it as far as it wants to go, then tighten, then loosen, then tighten, etc.

 

i warm up the car just to operating temp...
then twist on them...

 

This. Work it back and forth. This advice is gleaned from much experience with seized bolts.