Thermostat sheared bolt - engine out?

[MR2_GCY]

Hi... changed the thermostat today on my Mk2, managed to overtighten the bottom nut and sheared the bolt off... grrr... anyone had experience of replacing one of these studs? Is there enough access to drill out and re-tap and does anyone know the actual thread size please? Or is it likely to be an engine out job?

[BYRNEY1984]

It’s pretty tight for space but if you remove the thermostat etc you might be lucky and have a stub of the stud to grip with some mole grips or similar. As for drilling in there you will need a 90’ drill or just buy a cheap 90’ drill chuck. Also what rev engine is it. I’ve attached a pic of my original rev one after removing it so you can see the thermostat housing the rev 3 onwards is slightly different I may have a pic of one. As I fitted one to my car before the v6.

[MR2_GCY]

Its a 1996 Rev 3 (I think), there's no stud sticking out, sheared flat. A friend mentioned stud removal tool and 90 degree drill bit, will need to get a mirror in there to see it properly I think and centre tap it? Looks tight! Thanks for the reply.... any idea where i will get a new stud if i manage to get the old one out?

[BYRNEY1984]

Well thats crap. You’ll have to drill it out and tap it. I would just tap it mate or m6 standard thread and just use a standard bolt. Most Jap threads are metric fine and you never get a 13mm drive hex head. Always 12mm or 14mm lol