1998 Cavalier Overheating

[ptcfast2]

My 1998 Cavalier w/ a 2.2 is overheating rapidly all of a sudden. Within a few minutes the car overheats at idle. The coolant with then proceeds to bubble in the coolant reserve tank. The cap is doing it's job as the coolant will not escape the tank, but it will just bubble and make noises until I unscrew it. After it is unscrewed it bubbles out and over. The fans do come on to help. but they won't cool the engine off completely. The coolant actually bubbles before the Temperature warning light comes on anyways.


The owner I bought it from a few months ago said the low coolant light would randomly come on and then shut off. It was said it was checked out and it was just a temperamental sensor. (so the mechanic said). When set to hot, the HVAC system pumps out heat. The radiator hoses are hot. The oil & cap looks does not look milky and no moisture. I have noticed a "sputter" from the exhaust after you rev the engine and it falls back down to idle.

The car has 146,000 miles on it. It was not cared for the best as far as I can tell, so I've been cleaning it up and sorting out the problems one by one. I've been doing pretty good so far and the car has made great progress.

Would it be wise to replace the thermostat, water pump, flush the coolant, replace the cap, check the radiator for cold spots, & bleed the system before I even think about the head gasket (ugh!)?

Or is it something else entirely...

[J-Ri]

Sounds like the head gasket to me, if you're getting bubbles before the coolant boils, there's not much else it could be. Pressure test it and make sure that coolant leaks into one or more cylinders.