I have a 1999 Sunfire GT 2.4L twin cam, in the summer my car will begin to overheat on the hot days and I have no idea why. The AC works fine, the fan works, the coolant is good, no leaks other then windshield wiper fluid, and from my understanding if the water pump was bad or the thermostat was sealed close it would overheat all the time. So I have no clue what to do, or how to troubleshoot this.
Mysterious overheating
- Thread starter jjwenman
- Start date
Yes.
Not yet that's the next I was going to try.
And it comes on when thermostat gauge needle is in the middle.
Not yet that's the next I was going to try.
And it comes on when thermostat gauge needle is in the middle.
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cammerjeff
Well-known member
eliminate the fans, while you are checking the temp the fans turn on, I would check the radiator temps with the IR gun, you radiator could be partially plugged not allowing the coolant to circulate properly and when the outside air temp increases the decreased cooling area of the radiator may not be able to cope with heat.
Keep in mind that if the radiator is original it is almost 20 years old, they do go bad other than springing leaks.
The other things that can cause this issue is the water pump. The impeller can wear causing it to no pump enough coolant but not be leaking externally.
I would not just throw parts at it. Do some troubleshooting, does the lower hose collapse when the overheating takes place? Does the upper hose get hot when the engine overheats? Definatly use an IR gun to check the temps the cooling fan comes on, it will also tell you about what temp the thermostat opens, and use it all arounf the radiator. If they clog it is usually the lower 1/2 that clogs.
Good luck and let us know what you find
Keep in mind that if the radiator is original it is almost 20 years old, they do go bad other than springing leaks.
The other things that can cause this issue is the water pump. The impeller can wear causing it to no pump enough coolant but not be leaking externally.
I would not just throw parts at it. Do some troubleshooting, does the lower hose collapse when the overheating takes place? Does the upper hose get hot when the engine overheats? Definatly use an IR gun to check the temps the cooling fan comes on, it will also tell you about what temp the thermostat opens, and use it all arounf the radiator. If they clog it is usually the lower 1/2 that clogs.
Good luck and let us know what you find
I guess I'll have to invest in a temp gun lol, its going to be tricky cause it only does it on really hot days, or average hot days but stuck in traffic or steep hills. So far it's never come close to over heating just idling.
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i believe you can rent them you are checking to see if the readings you see on your gauge compare to the IR readings so it doesnt have to be a hot day, plus during prolonged idling the fans should come on.