I got to make an 800 mile road trip last week to rescue my daughter from her broken down car. It overheated and was spitting coolant from the exhaust pipe. BTW, 1997 Subaru Legacy Outback, 2.5 liter 4 banger automatic, 205,000 miles. At the Safeway parking lot in Anaconda Montana, I drained the coolant, replaced the thermostat, and refilled it with fresh clean 50/50 glycol. No Joy. So I dragged the car onto the trailer I brought with me, transported my girl back to college, and towed the car home. "Sounds like head gaskets" you say? Not so fast, grasshopper. They were done about 20,000 miles ago. No intermixing of the oil/coolant, no pressurizing the coolant. The car runs OK cold, but as soon as the thermostat opens, the coolant starts burping from the tailpipe. There's a bit of a vacuum (not pressure, like you'd expect to see from a head gasket failure) forming in the radiator when the car runs, seemingly sucking the coolant into the only place a vacuum forms on an engine: the intake. No obvious leaks of coolant other than to the exhaust. The local Subaru shop (Sue's Roos, experts in all things Suby and good friends of mine) are pointing at a possible gasket failure at the throttle body, just past the air cleaner. There's coolant ports in there that keep the atomized fuel from freezing up the body. Anybody seen anything like this before? Got ideas on where to look in addition to the above suggestions?