Was 101 outside...About 5 miles outside of town noticed my temp gage was almost to H so I turned off my ac and pulled into the gas station...Popped the hood, coolant spraying everywhere...let the car cool down for about an hour and attempted to drive it back home...But it overheated once and went into limp mode and had to let the car cool down again before I got it in the driveway.......I don't think this has nothing to do with air trapped in the cooling system because It's already been 9 months since I flushed it out...I'm hoping it's the thermostat and but might be the water pump(150,000 miles)...Any way to test the thermostat besides taking it off?

 

If the radiator's cold and the engine's hot, thermostat's broken.