2001 s80 overheating mystery
 

I'm really lost on this one. Driving on highway, I took a peek at my temp gauge and it was not reading temp. Within seconds the car cab filled with white smoke from the vents. Had the car towed and then found 4-5 inches of coolant on the driver side floor. Told me my heatercore blew so i bypassed the heater core at the fire wall. Still over heating, reservoir bubling coolant. Thinking thermostat now so i replaced it and it's still over heating.......what's left ? Water pump and head gasket ? Oil is clean, nothing leaking from the head gasket outwards. question is - before i spend the bucks on water pump or head gasket how i determine which ons of those 2 it is ? or could it be something else ?

Lee

Probably the headgasket blew too those engine are very sensitive when they over heat... Open the oil cap and look if its milky beneath it?