We have all done it, overtightened a bolt and blown out the threads. When a bolt starts to tighten up and then go suddenly loose, you know that the threads are toast and now you have a problem.

Dear Tom and Ray: I have a 2004 Chevrolet Suburban with a six-liter, V-8 engine. It blew out the No. 5 spark plug. I took the car to a Chevy dealer, who put in a Heli-Coil as a repair. Within 1,000 ...