Due u need a thermostat in a 2002 Cadillac Deville because I took mine out and it's running hot

[Clyde_6]

Car running hot

 

[greens]

Car running hot

Usually they run cold when the thermostat is pulled.

But yeah, you need that. Its what tells the water pump to start and stop.

 

[Karadjgne]

Yes you need a t-stat. It's what regulates temp to a normal operating temp, while giving the fluid sufficient time to cool in the radiator. Not having a t-stat means you are at the mercy of ambient temps once the engine warms up. Hot climates mean little cooling, engine overheats quick. Cold climates means your heater doesn't work very well and the autochoke is dumping gas because the engine isn't warm.