During driving today, the engine overheat light came on (bell rings too) and gauge went from mid point to HOT. Shut off engine, waited 2 minutes and started back up, temp gauge back to mid point. Within 3-4 minutes of driving, bell rings temp gauge goes to hot, says shut off engine. Shut down for 2 minutes while waiting for traffic, drove 1/2 mile to home, temp gauge was at midpoint, suddenly went to hot, made it into home garage and shut down.

2 hours later checked coolant, had to add 1/2 gallon but noticed original coolant (red color) leaking from underneath car unable to tell where. Need to have flat beded to garage I expect.

Started back up, ran for five minutes, temp gauge stayed at mid point.

Wonder if this is related to the original complaint of no heat in winter.

I bought this car used and problems began immediately. The heater would stop working, and the car would start to overheat. I took the car to the dealer and they would "bleed" the water line and the car would work fine for awhile. The dealer said the issue is that the motor sits higher than the water well and air bubbles get in the line. There is no fix its just a problem with the design. I say BS. I'm tired of dealing with this. The screw we have to loosen to bleed the line is not stripped and we have to find a new one. Its winter and the heater is not working because of this. I'm cold and broke. I will NEVER buy a chevy again.

I was stopped at a stoplight. Temperature gauge was at the top. Warning light said "idle engine" and "Turn Off Air Conditioning." I hit the gas when the light turned green. Problem appeared to go away. less than one hour later, I tried to turn on the heat. Only cold air came out. I will call the dealer tomorrow as it is still under warranty. Any suggestions are appreciated. I noticed a similar post here that described an air pocket in the cooling system. It said something about a blown gasket. I did run over a tree limb about one hour before this happened. I checked for leaks and sow nothing out of the ordinary. I bought the car 4 months ago at 25000 miles and added 4000 miles.