Low coolant light blinks

1998 Chevrolet Lumina mileage: 92,000. My car started running hotter than usual for about a week followed by an occasional leak from the driver’s side of the radiator. I put in some stop-leak and the problem went away temporarily. Then the car over-heated. I took it to a local service garage. They replaced the radiator and thermostat. I told them the car has specific servicing instructions for the cooling system. They told me it was done correctly. However, after the work was done the car got a low coolant light. I took it back they purged the system and got some air out. Then it did it again. When I run the car cold, it overheats. I stop it, it makes a gurgling sound, and when I start it the next time, it runs at normal temperature until the car is cold again. Do you think this is because they have not serviced the cooling system correctly? On the other hand, do you think this could be because of a different problem? If so what?

Your described symptoms suggest a blown head gasket. However first, examine the entire cooling system for leaks and then check the intake manifold gaskets.