New Motor Heat Cycle?

Since i got the new 99 4v in my car 96 gt it has had some heating problems. Some times coolant would come out of the tank and other times it won't. The coolant light goes on and off in the car all the time.

When the light goes on and stays on i go to see if the car is over heating but when i pop the hood the motor is cold. I really don't understand what the hell is going on. My friend says its going through a heating cycle. What do you guys think is going on?