Overheating Issue '97 Cavalier

wesley13

My friend has a 1997 Cavalier SL 2.2L that has a strange problem. When she is driving the car under normal conditions whether moving or stopped, she has no overheating issues. Additionally, when the car is moving and she turns on the heater and blower the car still doesn't overheat. However, if she come to a stop for more than a minute it starts to overheat. If, when stopped, she turns off the heater and blower, the car cools back down. Does this make sense to anyone? As background, she has had overheating issues in the past three month and has had lots of work done to include the replacement of the water pump, thermostat, radiator flushed, hoses reseated and the system checked for blockages, coolant drained and refill using vacuum.

Mr_Shiftright

No, that doesn't really make any sense unless she's running in the defrost mode and she has the type of car where the AC compressor kicks in to dehumidify the air--in that case, the AC compressor could add extra stress to an engine that is only marginally safe from overheating.

But, more to the point-----if there is a low speed overheat and not a high speed overheat, then the issue is probably AIR circulation, not COOLANT circulation.

So I'd check the operation of the electric cooling fan. Obviously her mechanics are chasing ghosts and not getting to the problem.

wesley13

Appreciate the information but honestly, still doesn't make sense. Sitting at a stop light without the heater the car is fine. She turns the heater on and it starts to overheat. She turns it off and the begins to cool back down. Almost sound like the operation of the heater fan is somehow effecting the operation of the cooling fan. Don't know if that is even possible. But again, appreciate the advice.

dustinj1

Did you try to see if the Coolant temperature sensor Is bad or not if haven't I would try that just in case is the car overheating at all after the gauge is reading in the red zone if it isn't smoking then most likely that the Coolant temperature sensor went bad meaning that its saying its overheating but its not. That's what i do believe is happened to mine... Because mine was in red wasn't smoking or anything so I drove it didn't hurt it at all because the sensor was reading it wrong just a option also could have a air pocket when thermostat got changed