When I drive the car overheats and there is a gurgling sound, what is causing this?

The check engine light is on and has been on for some time but just recently there has been a gurgling sound that seems to becoming from just behind the radio in the dash. The gurgling sound only happens every once in a while and usually only doesn't last long and if I park my car for class and go back home I do not hear the sound. Just recently the gurgling went away but the temperature dial rose all the way until the temp light came on and then when I was about to pull over the dial started to go back down. I checked my coolant and it was empty so I refilled and again then next day my car started to overheat again but this time I heard the gurgling sound also. As I was about to pull over, the dial went down again. I have not had time to check the coolant level yet but what cold be causing this to happen?