My #7 Spark plug keeps working it's way loose. I'll tighten it up, drive it for about a week or two and then the car will start to smoke at WOT. I pop the hood and the #7 plug is loose again! This has happened a few times already and it's getting pretty annoying. I was thinking about putting a very small dab of lock tite on it and seeing if that keeps them in there. What do ya'll think? Also, the rear two exhaust bolts on the drivers side header above the number 7 plug keep working loose as well. Lock tite for those as well?

 

That's not right....

Maybe the hole is stripped out? The plugs shouldn't move at all.

 

No, the plug will screw in nice and tight. It just works out for some reason. I don't know what to do with it anymore.....

 

Is the ring still on the threads? Either get a new one or swap another cylinder to see where the problem goes.