I had a new water pump installed on my 96 voyager yesterday. The thermostat was taken out before hand though and i let the guys at the shop know that before they worked on it. When i got home today though i saw the thermostat on the back seat so i'm not sure if they replaced it or just didn't put it back in for me.

my question is can i unbolt the housing and check without draining the coolant or messing with anything else?

 

You will need to drain some coolant to below the thermostat or it will spill out when you remove the housing.

 

You should be able to check if the thermostat is in the vehicle without taking anything apart. All you have to do is with a cold engine start if and then remove the radiator cap watch the movement to the fluid as the engine heats up and starts to cycle the thermostat you will see the fluid flowing when the thermostat opens and stop when it closes. You can do this with a engine that is already hot but you need to be VERY CAREFUL when removing the radiator cap.

 

thanks for the feedback. i drained some of the coolant and it turns out they just replaced the thermostat.