Cool plug tool

[Guest]

Back-tap spark plug thread repair tool

http://www.starrproducts.com

[Anonymous]

That's a cool tool.

[Anonymous]

I think I'll just keep being really careful.

I think I'll just keep being really careful. I can't imagine that once damaged the threads could ever be good again. If you tear up 50% of them and restore 20% you still have 30% gone or still not what they should be.

How long could you expect those threads to hold up? You might buy yourself a little time, but sooner or later they will give out again.

[mdole]

Re: I think I'll just keep being really careful.

I think I'll just keep being really careful. I can't imagine that once damaged the threads could ever be good again. If you tear up 50% of them and restore 20% you still have 30% gone or still not what they should be.

How long could you expect those threads to hold up? You might buy yourself a little time, but sooner or later they will give out again.

I had a Suzuki Sidekick that blew a plug out of the cylinder. When I checked it the threads were there, only slightly damaged and needed to be cleaned out.
I figured that with 175k miles on the engine I'd try the quick fix so I put a rag covered with grease through the spark plug hole to catch any metal chips that dropped into the engine. Then I used a tap to case the threads. I carefully centered the tap over the spark plug hole and ensured it was perpendicular to start and carefully worked it down the first couple of threads then fully cased the threads a little at a time.

I fished out the rag and only had a couple of metal chips on it. I then cranked the engine a little to clear any remaining chips out of the spark plug hole, replaced the spark plug and it worked fine for the next 25k and then we sold the car and as far as I know it's still working fine.

I had replaced the spark plugs with Bosch Palladium plugs just prior to the plug blowing out. I put in a new set of ND plugs after repairing the threads and found that comparing the threads on the plugs the threads on the ND had a significantly larger diameter than the Bosch so I think that the plug blew out because the threads were too short to hold under compression. The NDs fit much better. I hadn't notice this before and had run Bosch Palladiums in other vehicles so I think this may have just been a bad set of plugs.

The repair worked because I had sufficient threads left to case out a few bad spots and clean them up. In a lot of cases only the first few threads are damaged as when a plug is started and cross threads.

For a case like mine or a plug that?s cross threaded and not run all the way in this tool should work fine.

Mike