[rjSupra]

I just did the same thing while my car was stranded on a city road for 2 days. I did the water pump, a few belts and the T Stat and snapped the lower bolt off into the water outlet housing that holds the T Stat. Damn weak ass-ed 20 y.o. Japanese steel. (wtf). I also snapped the bolt lock in the tension adjustment the alt belt with very little force on it on the same repair. Damn weak ass-ed 20 y.o. Japanese steel.
I am planning to remove the whole water outlet housing and then get it on a workbench and drill it out.
I will, just in case, remove the T Stat once again, to see if there is any amount of bolt over the surface I can latch onto with vise grips.
I also remember doing something like this on another car or moto, snapping an older cheap ass steel bolt (no I am not He-man).
I took a thin drill bit with a good drill and drilled in a hole, then a larger hole, then a larger one... and on the third bit the bolt more or less started falling apart and just spun out backwards fine. I used a replacement identical bolt and all was well. Hoping for same results.
I also have this stupid coolant mystery leak to deal with so getting off that housing will give me more clearance to try to find where my car is dumping 1 gallon of coolant in 15 minutes after it revs over 2000 rpm on the highway in top gear or goes up a super steep hill... It ain't the water pump, it ain't the T Stat, not the radiator or upper or lower pipe... Hoping and hoping it's the 90 angle short hose under the water outlet... got that Gates part and two screw clamps for $6.39 today.