[denisond3]

You should be able to see coolant by looking down into the 'overflow bottle' on the curbside of the engine compartment. It this is over half full, I would assume your cooling system had enough liquid in it.
If your temp gauge is staying below 1/4, then either your Engine Coolant Temp Sensor (ECTS) is senile, or the thermostat is stuck open. The ECTS on Saturns very commonly ages and doesnt bring the gauge up - and I think that is more likely than a stuck thermostat. So I would recommend you first change the ECTS sensor (its on the side of the engine head facing the battery, and probably hard to see due to the air inlet tubing). I think there are instructions about doing this on this site. If the gauge still reads below 1/2 when the car has been driven for 15 minutes with a new ECTS installed - then I would believe the thermostat was stuck open. But with the engine idling where its not super breezy, the coolant will get warm then hot, in 15 or 20 minutes, even if the thermostat IS stuck open. I wouldnt try this with a bad ECTS, since I am not sure the radiator fans would come on as they should.
And you can be looking for where coolant is leaking out during this time. If you fill the overflow bottle to the brim, then start the engine and let it get warm; some coolant will run from the over-flow tube, due to expansion when the engine is warm.
It is possible to have the cooling system pressure tested. This is done with the motor shut off, and it pressurizes the cooling system with a hand-pump. Then you crawl around the car (under it too) looking for where the coolant drips from.
A common place for small leaks is from cracks in the plastic side tanks of the radiator. They wont be big, so look for them with a good light. Mine were on the tank that was on the drivers side. They were near the top, so the leak would stop when the water got low.
With the engine running, it is hard to spot leaks from a bad water pump, because the serpentine belt is spinning close by, and will splatter coolant every which way; and the a.c. compressor and radiator hoses keep you from getting a straight view. To have a good view upward from underneath the engine, you would need to remove the bottom splash shield. Thats probably why the bottom splash shield was missing from our car.