dudesqueak

When I installed my headers, I also installed some NGK TR55 plugs. After a few weeks, I noticed that I had an exhaust leak at the heads. I figured it was just because of the stud that my buddy broke off when he helped me install the headers. I planned on taking the heads off and removing the broken stud later. Yesterday, I noticed that the leak was worse than it used to be. When looking under the hood, I saw that some exhaust air was hitting one of the spark plug wires hard enough to shake it. Upon further investigation, I found that the spark plug was loose. So I began to thread it back in. I worked my fingers raw and spun that forever it seemed like, without the plug ever actually tightening. The plug definitely seems like it is threaded in farther than it was before, and still turns out if I try to, so I don't think it's stripped. When I used the good ol' search function, it seems like everyone else who has had spark plug loosening problems had TR55s. Does anyone have any ideas of how to fix this or what type of plugs DON'T loosen themselves over time?

07NBSChevy

iTrader: (1)

So when you thread the plug in, does it actually get tight? You say it never actually tightened but yet you say you don't think it is stripped?

I am pretty sure the actual plug, NGK TR55, is not the issue. If the head or plug threads are not stripped, just put some anti-seize lube on the plug threads and torque to 11 ft-lbs. If it continues to loosen, then either the plug threads or the threads in the head are messed up.

Crf450r420

iTrader: (1)

I prefer gaskets plugs over the tapper seats. We use a lot of the NGK 4554 or R5671A-8 for the boats, but I'd run the 4091 / R5671A-7 in a car if those are even hot enough. They don't make the race plugs in -6 and I don't have another number in my head to offer.

As for the fix. It sounds like you need to pull the head and fix that bolt also and while it's off it will be easier to fix the plug threads or even figure out how bad they are to begin with.