Do I need a waterpump?

Other than an obvious overheating problem, what other signs should I look for to figure out if I need to replace my water pump.

There is a rythmic squealing sound coming from the engine bay when driving and the car has dropped about a quart of coolant in the garage.

do you have the cam driven waterpump? Im assuming its a 3.0L duratec?

do you have the cam driven waterpump? Im assuming its a 3.0L duratec?

I can say that I know. I don't like the sound of it though. I'm not sure if the specs of my Sable got posted or not, so here goes:
It's a 99 that I bought used 4 years ago. Of the two possible engines, it has the smaller.
It's usually been quite dependable, other than needing a battery, so this is my first problem with it.

do you have the cam driven waterpump? Im assuming its a 3.0L duratec?
get your car up to operating temprature and turn your heater on and see if you have heat. sometimes a thermostat will cause this too if you have no heat it is one of the two or take your radiator hose lose from your water pump and stick your finger in the neck or a screwdriver to see if you can turn the impelar on the shaft if you can the waterpump is bad