Tazmanian_Dvl

Honestly it doesn't look like the plugs were burning too terribly bad. Looks like your car is running a tad but rich but that's not really a bad thing. Another thing (please don't take this as I'm trying to rip on you because I'm not) it actually looks like the plug that failed was cross threaded into the head when it was installed and the force of the compression over time worked it loose and tore the threads out of the head and off the spark plug. The reason I say this is because all things equal and if the plug is threaded in correctly the threads on the plug are going to be stronger then the threads on the aluminum head and the threads on the head should give before the threads on the plug (most of the time the plug threads are made of steel, at least the ones that I've used and I mainly stay with AC Delco plugs simply because I trust them) I did this in my younger days when I got my first car and decided to do a tuneup. Couple months after I did it I got the God awful sound you're talking about and I had to helicoil the head and replace the spark plug (the threads looked exactly the same why yours did and I have to admit that I did cross thread it when I put it in).

Sh0nuff

how much did it cost for the helicoil?
I just went to change my plugs and to my surprise...out poped a helicoil on a plug...
evedently the person who had the car before me put one in, i put some locktite in and got it torqued back down and seems to be ok but i want to take it in and get the helicoil replaced, i just need a idea as to how much i am gonna be outa pocket...
thanks guys...
I hate surprises.......well like this anyway..

Johnboy12358

This could be totally possible, but I cant be sure, I mean I didnt force the plug at all... Who knows, I still stand by the "Zex plugs suck" statement though. The NGKs run my car SO much better now, like night and day.

$160 for the entire job on mine.