Looking for some advice on what you guys would do to repair this.. the aluminum intake on my 79 caddy has a water temp sensor that has crossthreaded and stripped the aluminum a few threads deep, its like a 1" threaded hole or so. its big. I was stupid and started rushing the job since it was getting late and i was tired, all the holes had paint in them so they felt a little tight at first but all threaded fine except for this one. it started tilting and crossthreaded about halfway down! uggg. i backed it out and seen it mangled in there! I dont want to replace this manifold AGAIN. I dont need this hole as there are 2 up there and I only need one. what do you think I should do?? could I get a self tapping fitting to plug it or something?
If it were me, I'd figure out what type and size of thread it is and beg, borrow, steal, or buy a tap and chase the threads. Hopefully there is enough meat left on them so it will still seal after cleaning up. Apply some high quality thread sealant. I would not attempt to use any other option. Even if you have to pay $40 for a special tap, it could be far less expensive than the alternative.
should be a pipe thread. NPT. I say get the tap and chase the remaining threads, cut a few extra threads if needed. and if you dont need the hole, seal it up with a plug and some sealer or JBweld on the plugthreads. good luck
If the above sugestions do not work you can see if they make a plug that is large enough. They press in and you are ready to go. Just be sure to use a drill press to clean out the stripped threeds. They need to be very straight. If the intake is still on the car, be vey carefull and sneek up on the corect size bit size. Good luck
Before you plug anything, consider Heli-Coil. They offer inserts for pipe thread. http://www.helicoil.com.sg/HeliCoil-Pipe-Thread-Inserts.htm Devon
Ok, Looks like i have some good options, thanks guys. I talked with the maintenance man here at work and he offered to loan me a tap for the size i need. Since i have a few threads left down in there maybe i should try this route and chase the threads. Do you think they will be strong enough after that? Or would i need some jbweld or something to help keep it locked in. And will it be removeable after that?
depends how bad the threads are. definitely chase with a tap. If you can cut enough threads it might seal fine, the pipe thread is a sealing type of thread - it gets tighter as you thread the plug in. Then again if the intent is to not use it, but just get it plugged well...then Id concentrate on a good sealer. JBweld will seal the threads up very well, in a more permanent fashion. teflon paste would work well if you have ~good threads to work with and want to remove the plug at a later date. can always try the paste 1st and see if it works than JB it if it leaks.
You're not dealing with much pressure so it won't take much to seal it. The teflon thread sealant is top notch stuff. The goopy stuff that comes in a tube is better than the tape.
