Is there another way to diagnose a blown head gasket outside of checking the oil

What is your question?

Light on, add coolant. As I was driving, the thermostat was going up. I put the heat on high did that. Car had white smoke, then steam was coming out from under the hood when I would stop. Air started coming in cool. Got coolant in it and we saw it start pouring out under the left side of the engine and a hose disconnected .I drove it before the rest ran out. a very short distance. I checked the thermostat still at 1/2 when i got to the closest destination. Next day I checked the oil thinking it could be a head gasket if the coolant had run out. I may have needed to turn the car on and then check now that I think about it. It looked fine. I then had it towed and they found two hoses that needed to be replaced, one coming from the radiator. The other I don't know. Now they want to replace the thermostat and flush heater and then see if it has a blown head gasket but that is spending 600.00 just to find out if the head gasket is blown? They also drove the car today.

How long has your 2006 Saab 9-3 had this problem?

5 days