How do I tell if my water pump is going bad? My Chevelle over heated. I replae the thermostat. This seemed to stop the over heating, however when I get out of the car I can hear the fluid "gurgling". Any help would be appreciated.

You need to get yourself a "Mechanics Mirror" and look under the water pump. There you'll find whats known as a "weep" hole. When your waterpump goes bad you'll see a coolant trail out of that hole. The hole is there to vent pressure within the pump when your engine heats up such that the pump shaft seal doesn't fail prematurely.

I suggest a "Mechanics Mirror" because they have a collapsable shaft handle and a pivoting mirror so you can get them into tight places like right under your waterpump. Most auto parts stores carry those mirrors. They are not expensive.

With respect to gurgling I suspect that you have air in your coolant system. I'd look into how full the system is.

Good luck :)