We made it to a service station with a sandwich shop and I called the cavalry and bought the boys lunch so they wouldn't resort to cannibalism (we had over a half-hour to wait.) The engine compartment was full of vapor, but the smell inside the passenger compartment wasn't very strong at all. There was a growing puddle of orange coolant on the ground under the car. After my wife arrived and we took the boys to their stuff, we bought a few gallons of water and drove the Camaro home. It was getting hot by the time we made it home (only about a 10-mile drive, if that) but it made it without adding more water along the way.
I suspected a 'sploded heater core, but my dad pointed out that this should fill the cabin with sweet, sweet coolant fumes. So I suspected a blown attachment where a heater hose connects to the firewall.
So today I needed to jump-start my old truck anyway, and to kill two birds I started the Camaro and let it run. No leaks. I checked, and it was low on water, so I added some, but . . . . still no leaks. Then I looked inside the car--the heat was pegged again. This is making me suspect the water pump is dead, and all the leakage Friday was from the pump's release holes. The problem with that theory is that I was sure the coolant vapor clouds were coming from the rear passenger side of the engine compartment--which is also where the hoses go into the heater core. I have a long history of love-hate with GM water pumps. The hate is paid in full; I expect the love to start any year now. I was too chicken to open up the radiator or a hose with the engine so hot (though the radiator itself didn't feel very hot at all--another reason I think coolant is not circulating.) So I figure tomorrow I'll disconnect a hose and see if the pump is circulating water. If it is, water should shoot out of the hose, even if the thermostat hasn't opened yet, right? I don't think a water pump on this thing would be a HUGE deal, but I thought I'd ask and see if anyone has a better idea.
What's puzzling me here is why I can't induce a leak today? I had more or less pure water running in an engine above 260 degrees. It boiled at around 212 degrees, right? Why isn't it shooting out all over the place?
UPDATE: From comments, it sounds like the original suspicion of the heater hoses or their fittings was closer. These are the hoses for a 1995 Camaro with a 3.4L V6. I'll pull the hoses today and see what I can see. I'm hoping it's an issue with the fittings on the hoses themselves, and not on the heater assembly. I'm imagining a lot more work if that's the case.