Apparently our 02 Grand has two loose plugs one on the front and one on the back. This is seen by vibrating plug wires. They can be hand tightened by grabbing the boot and turning but after a few seconds the motor vibrations and the coiled wrap of the wire cause it to twist back out a little.

Anyone else ever have this issue?

We have to go to Oreilly to warranty an EGV valve and while I'm there I was going to pull the 2 plug wires (the wires are under warranty with Oreilly also so if a wire pulls the spark plug connector I'm there and can warranty the wires also vs being stuck at home with no transportation to warranty the wires) and retighten the plugs.

I've probably changed plugs 60-100 times over the past 30 or so years and have never seen any loosen. Usually if anything they are a total b$#$@ to break loose.

Could this be signs of the threads failing in the head or just an off the wall thing? I always run them in by hand until I can't turn by hand then snug them up with a ratchet. So I know they were all started straight.

 

Not using a torque wrench on plugs in these newer aluminum engines is just begging for trouble. If they're torqued properly, they don't loosen up. Period. If you over-torque in an aluminum head, you can damage the threads or distort the spark plug shell, causing leaks. If you under-torque, it can shoot right out, taking the threads with it.