possible thermostat stuck open?

[RyanD]

I was coming down from a mountain pass pretty much coasting down the whole way. As I was going down I'm temp gauge would fall all the way down to bone cold. I pulled over and check the coolant. It was just Luke warm.

Is this a sign I need a new thermostat?

[steelbluesleepR]

Take the thermostat out and put it in a pot on your stove with water in it. use a thermometer and measure when it opens up.