Remove broken stud in thermostat housing

I once snapped a bolt off in the timing cover of my V8...

I then snapped a drill bit off in the whole that i drilled - cheap drill bits are dirt!

I then bought a really expensive bit, with a special coating.

Nedless to say it pissed though the broken bit, and then though the remaining stud.

Lesson learnt - dont snap bolts in timing cover, dont use cheap drill bits on important parts!

Also buy a commercial quality "easy out", dont buy an el cheapo as you'll end up having to drill the easy out as well.

dont use cheap drill bits

Life is too short for cheap tools - but I guess we all do on occasion

MIG a nut to the remnants and use that to unwind it.

Tungsten burr?

AJH

Possible approach. Bolt the housing on with the two screws that came out.

Pick a drill that closely fits into the third hole at the broken screw. Drill enough to make a centered cone in the broken screw.

Then you might drill out the screw for a tap. Or maybe drill for a helicoil insert. If you drill for an extractor, use a freezing penetrant to break the rust bond. The screw is hard, so you need good drills and a steady hand.

I missed any earlier replies along with the original question on this. So don't know if welding a nut or similar onto the remaining stump has been suggested. See.

Mike