My son owns this car, and recently had the upper thermostat housing (where the upper water hose connects) split. He removed the large black housing on top of the engine block (sorry, I don't know what it's called), and found that one of the bolts that connects the thermostat housing to the engine block had snapped off -- actually, it broke in the middle, with the bottom half still threaded into the block housing.
Anyway, he's been trying to get this broken bolt out with no success. We've tried drilling into it so an extractor can be used, but this bolt piece is made of extraordinarily hard metal -- we've broken about a half a dozen bits. We did manage to get a tap into it once, but then the tap snapped off. And, there's not enough of the bottom of the bolt sticking out so we can unscrew it from below.
Any suggestions on how we can get this broken bolt piece out? I thought one of you might have had the same problem and could give some advice. Thanks!!