Undiagnoseable overheating. when running the air conditioner for long periods of time (i.e. road trip, less than 90 minutes) the air conditioning stops working and the coolant blows out of the overflow tank. this has happened multiple times. we've replaced the radiator twice, 3 different thermostats and i've had the head machined and checked for leaks, the head gasket and all associated gaskets with that job replaced and still cannot drive without coolant spewing from the overflow and eventually causing a rise in temp on the dash gauge. date of occurance below is an estimate, i've been fighting this car for so long i have no idea the first time the issue arose.