HELP - thermostat housing bolt sheered off in block.

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So, today really wasnt my day at all. One of the bolts for the thermostat housing wasn't feeling good today, decided to sheer off inside of the block. I was left with a 1mm portion of the bolt.. the rest is inside of the block. I tightened up the other 3 bolts, filled it up with coolant, and sure enough coolant started dripping out of the bottom part of the thermostat housing (it was the bottom left bolt.)

How the HELL can I fix this? I'm totally out of ideas. Is there some sort of silicone sealer I can use around the outside of the thermostat housing? There's no way for it to dry.. I'm freaking out, have I just basically screwed up my entire engine block?

An entire weekend of working on my car and now this..

Will I have to drill out the hole and re-thread it? The radiator is totally in the way.. no possible way to get a drill in there.

Please help ASAP.


posted by  E36DJ

That's interesting the thermostat is incorporated into the block. If you were able to get a drill in you could then attack the thing with an ezi out or use a self cutting screw to temporarily hold it.

You really should think about at least partially draining the system and remaking the joint with some good sealant that is allowed to cure.

posted by  Wally

Agreed. I promise unless you drill it out or re-tap it you will never get the proper seal again and will lose coolant. I've tried everything short of tack welding to fix this kind of problem and it just wont happen.

posted by  Blue_Frog

my old college teacher showed me one method of getting out broken bolts that has always worked, when the bolt shears off it usually leaves a little bit of material on the end of the bolt , sometimes you can get a chisle or a punch and just lightly tap the little nib of metal in the CCW direction and it will start to spin, to date i've broken 3 major bolts inside of major components and to date all three times i could get em out with the chisel and hammer method good luck

posted by  BanffAutoSpa_ap

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