Heatwave help needed- 2001 Chevy Malibu

No joke, we have to keep this car running as we cannot afford to get away from it at this point. So, here’s the lowdown as we can recall so far in the saga…

Summer 2005- multiple overheating/low coolant light illuminating quickly led to diagnosis of cracked head gasket. Head gasket replaced.

Spring 2007- routine check over led to one shop advising the head gasket seals were leaking (we had no indication of any problem, so this was a surprise). We took it back to the shop that replaced the head gasket less than two years earlier, and they found no problem. A third opinion from another mechanic also found no problem.

Now (Summer 2007)- No problem on a 1,400 mile trip. But, a week later, we cannot keep coolant/ water in the reservoir and the temp light is coming on and the needle is steadily rising to the red danger zone, eerily reminiscent of two summers ago. The car is essentially disabled and college classes start up again tomorrow. ANY insight is greatly appreciated!

Some more things that came to mind…
Fall 2006- Fuel injectors cleaned (3 part process: Motovac machine, spray and fuel additive)due to “stumbling” on acceleration up hills/general hesitation. The fuel filter was not changed at this time, and this was something we were contemplating since the Motovac didn’t seem to make a significant difference.
Summer 2007- Routine oil change and we changed the spark plugs.
Mom and I need some suggestions- any input is appreciated!