So I was bored today and decided to go ahead and change the spark plugs in our 2006 Honda Pilot at 96K miles. First one comes out and new one goes back in just fine. Then I move to the middle plug in the front bank and as soon as it broke loose, I could tell something was wrong. It feels as if it is crossthreaded or something. Makes a very slight grinding noise if I try to loosen it anymore and I can't loosen by hand. If I try to tighten it back up, same thing. I haven't turned it much since I could tell as soon as it broke loose something was off. What do I now? Keep loosening it with the wrench or am I just doomed for a more expensive repair by my mechanic?