I have a '03 s80 2.5 T. About 2 weeks ago, I had a message that said the coolant was low, stop engine, which I did and added coolant. Within an hour, my car was smoking and all the coolant had drained out in the parking lot. I took it to the mechanic and they said it was due to a cracked reservoir which I had replaced. A week later after an hour and a half drive, I stop my car and again it starts smoking and dumped out the coolant. I returned to the mechanic and they said it was just a hose clamp that came loose. They fixed it and as soon as I got home, the same thing happened...coolant dumped out, smoke, over heating. Any ideas? is this a head gasket issue or possibly that the clamp just came undone again??

 

It might be the little plastic elbow inside the timing belt cover. Search the forums about it some posts have pictures.

 

You've probably roasted the cylinder head by now.

 

A bad head gasket does not make a car over heat...a stuck thermostat is most likely your cause...or bad radiator. But if it shoots up real FAST it's a stuck thermostat. The only time a car will overheat from a broken head gasket is when all the coolant leaks out....careful or you will blow your head gasket from so much overheating.