Weird cooling problem Buick 300

I got a weird (to me anyway) cooling problem on a Buick 300. The bottom hose is hot but the top one is not hot at all. Their is alot of pressure in the radiator. It is pushing water out into the overflow tank and onto the floor. I cracked the radiator cap and it began to rally come out. I put it back on quickly. The coolant was not that hot either. My quess is the t-stat is not opening. Or the water pump is shot. I'm kind of leaning towards the t-stat though. Any thoughts? Thanks, Todd

 

Remove the thermostat temporarily and see if it makes a difference. While it's out, check it in boiling water to see if it opens.

Bob

 

Todd, there's an easy 'seat of the pants' method to check the thermostat. Pull it out, submerge it in a pan of water on a stove, and if it is not fully open before the water boils then it is n.g.