The truck is a 93 PU with the 3.0. My wife came home today and the # 5 plug was popped out. The threads looked okay so i tried to thread in a new plug.

No luck.

I decided to chase the hole with a spark plug thread chaser. The thread chaser "snugs up". However, when I try the spark plug, it seems as if it only spins and does not engage the threads at all.

What gives? Are the threads junk? Any help or guidance would be most appreciated. Thanks

 

sounds like the threads are stripped. heli-coil may be an option but you have to be very careful about the spoils from cutting new threads.

 

Threads are stripped. How much of a pain is it to install the HeliCoil (or equivalent) and how long does it last?

 

if done right itll last a long time, the problem is, as Abe already stated, that the little pieces of metal get into your combustion chamber when you rethread the hole. on your #5 id say a real pita.

 

Helicoil is really the only option. Helicoiling itself is fairly easy - you drill out the hole to a specified size, tap it with a special Heli-coil tap, and install the little insert.

Like everyone else has said, the issue comes with the debris you are forcing into the combustion chamber. It's possible to install the helicoil, then stick a shopvac with a small, flexible hose into the chamber. Or you can try and blow any metal shavings out with an air gun. Is it possible to get everything out? Yes. Is it likely? Probably not.

The #5 plug is kind of a pain in the ass to get to, but if you remove the charcoal cannister and use a wire tie to get some of those vacuum hoses out of the way, it's not too bad to get to all in all. Take the head off and you don't have an issue there, but, well, you have to take the head off.

This is one of those jobs where I would pack up the tools and take it to a mechanic, personally.

Edit: http://www.fjr1300.info/howto/helicoil.html here's an interesting link with a pictoral how-to on installing a helicoil. Shows how it works, anyway.

 

Heh, im in the same boat. Crossthreaded number 6 spark plug. I should really get it fixed.

 

Do it the redneck way and JB Weld that sucker in.

Just kidding, don't really. I worked for a guy doing computer repair several years ago, and we had to use these Chevy Astrovans as service call vehicles. One of the plug holes on the van stripped and blew the spark plug out (?) while it was on the interstate. They just JB Welded the plug in. This was 5-6 years ago, and the van is still being used, so I guess it worked out .