broken bolt
 

My sons 88 accord started overheating. Got it home and when car was hot, the top radiator hose wasn't hot. So figured the thermostat. The top bolt on the housing broke off when I was taking it out. Any Ideas on getting this out? I looked up easy outs on int. and sounds problamatic. Boiled his old thermostat on the stove and it never opened, so I think a new one will fix it. Any Ideas will be much appreciated, i'm not sure what to do. Thanks in advance, bob

you might have to drill it out and retap it.......or might be able to use an easy out

If there's any kind of piece of metal sticking up from that bolt , you might be able to get a pc of it like desert says...

Hey dersert! Have you been to the mod forum today?
If not go there please...
Angelo

If the bolt broke off as it is seized it isn’t likely an easy out will help unless you can heated it up. Is there enough of the bolt remaining sticking up to grab onto? When drilling out a bolt it is hard to determine the center unless it is flush with its surroundings. The threads make it confusing. You could use a mapp gas torch to heat up the bolt but you have to be careful not to melt the aluminum housing and if you have enough material to grab onto you should be able to get it out. If you end up drilling out the bolt and if you don’t hit the center you could drill it oversized and use a helicoil insert. I have had good luck drilling with Craftsman’s Cobalt bits.

If you hit center you could drill it out to a point where the old bolt is just the threads and then fold it in with a screwdriver and pull it out. That all the ways I have used others will have more.

Looks like the thermostat housing #10 can be removed pretty easily. That might make it easier to drill the broken bolt?
http://www.hondaautomotiveparts.com/...e001_e1501.png
(This is FI, but it's a similar arrangement for the carburated engine.)