I've had to replace water in the overflow every month or so. The light would come on and warn me. We recently went on a trip and got a few miles out to see the temp guage going up fast. The warning sound as well. Pulled over immediately and let it cool. The water level was fine though. It was steaming out of the overflow tube as normal when hot.
A tow truck mechanic said head gasket bad (1,500 repair) but I'm not convinced that is the problem.
Tags: 2001, Malibu, overheating