Great. I removed the coolant block drain plug and now I can't get it to screw back in. It's got fine threads. It's in a really hard to get-at place from underneath the car, but I did manage to remove it. Needless to say, it was tight getting off, but I got it off. Now it seems about impossible to get the threads started again to screw it back in. Looking closely at the threads on the plug, there's a couple fairly obvious buggered up areas on the first thread, as if the part of the thread squished a little so there's metal from the thread blocking the groove. Don't understand how it happened; all I did was unscrew the plug. It was really tight turning all the way out, with no real visible seepage or leakage seeming to happen, until right at the end it more or less popped out hard and all the water came gushing out. Maybe that force the way it happened ruined that thread. So I guess I'd either try to re-thread the dang plug somehow or have to get a new one somewhere?
And my luck I suppose same thing might've happened to the threads in the engine block too. No fun

 

If you go to a site like hondapartsnow, you can find the plug in the cylinder block/oil pan section. You should be able to get it from the dealership.

I'd definitely try fixing the threads with the proper die.

 

Don't have a dealership nearby, and the closest one never has anything I ever need in stock anyway. Will probably check out hondapartsnow per suggestion. Would love to just be able to fix the threads but don't have a die or know the proper size anyway. Maybe if I could somehow find out the thread gauge I could check around at a machine shop or somewhere where they could do it for me. Not sure how much they'd charge for as compared with total cost from place like hondapartsnow. I wonder what I did to ruin the thread anyway. Twisted it funny at the end or something? All I did was unscrew the thing. Thanks

 

Maybe go to an autoparts store with the plug and see if they have something that matches?

 

I'm not feeling that lucky. And I'll see in about a week from now, when it finally arrives, how lucky I get with my freshly ordered new drain block plug (& washer) from hondapartsnow that cost me 23 bucks and change including the shipping. Dangblastit anyway.

 

I've had success cleaning up threads with a triangle shaped file.

 

As I mentioned, these are (relatively) fine threads. But sure, if I can get my hands on what seems an appropriate size, small enough, triangle shaped file, I'll certainly give that method a try. Thanks!

 

They make something called a thread file. It's got teeth that match the thread pitch, but since it's a file you don't have to know the diameter. Each file has 8 different pitches.

 

I've never heard of such until now. Here's one probably like described/quoted above. Looks like just the ticket perhaps to fixing my plug threads maybe. Except I'd need to be certain somehow about what what thread pitch I'm dealing with on the plug. Any tips in that regard would be appreciated, as I'm relatively clueless at this point. Thanks.

 

Your best bet is to take it to parts store or hardware store and try to use the gauge most stores have.