Replace your thermostat in the cooling system. It works fine on the open highway because the air flow is great enough to cool the motor.
if the fan has stopped spinning but still works when tested with external power
Check your Pulse Width Modulator ( Radiator Fan Relay ) it is located behind the ( looking at the Jeep) left front headlight near the bottom . You must either cut a hole there in the plastic or remove the entire front bumper. The item is avalible at discount on eBay or from the dealer it costs $120
good luckAnswerTry checking the radiator fan. It's likely that the motor has failed or the relay is bad. AnswerSound like your fan stopped working. Same happened with mine. It's a 2000 Grand Cherokee. OEM replacements are expensive $350.00 plus. Aftermarket is much cheaper $150.00 AnswerTry turning on the AC to see if the radiator fan comes on. It should.If the fan does not come on check the fuse on the wing in the engine compartment.If the fuse is OK turn on the AC and check that the motor has voltage to it at the motor wire conector at the fan. If there is no voltage here it is probably the relay, if you get voltage then its propbably the fan.
The relay is dificult to find, under the passenger head light on top of the wing - difficult to see let alone get to.AnswerStrange situation with my 2000 GC. Fans spins fast if supplied directly with 12 volts. Seemed to be spinning, but slowly when connected to the wiring harness. Found that only 6.9 volts were getting to the fan. Not sure where to go from here. Fan is ok (?), relay works (or closes with some added resistance?), and logic seems to try to spin fan when hot, or with A/C on. Anybody know why less than 12 volts would be supplied? AnswerYou may want to check the viscous fan clutch as well as the electric fan as I have replaced 2 in 6 years on my 99 jgc (a lot of slow traffic here). An easy check, but not profesional, is to listen for the jet takeoff sound when you start off cold in the am, which should go away in a few seconds.
A lack of water in your cooling system will cause your 2002 Pontiac Sunfire to overheat. A malfunctioning thermostat can also cause it to overheat.
If it's overheating, then it might be several things like: low coolant level, improper coolant mixture, faulty fan on the radiator, or it's relay that controls the fan. Or maybe even the water pump is on it's way out.
You are not giving enough information to get a reasonable answer. It's like asking why it won't start. Any, and I mean any, detail would help. Are we talking about the engine cooling system? What are the symptoms that bring you to the conclusion it is overheating? Have you checked the coolant level? What year and size engine? Does it overheat only when stressing the engine, like climbing hills? Does it overheat only in traffic and okay on the highway? Does it overheat when the car is idling? Has the head gasket ever been replaced?
the thermostat probably went bad try to change it or take it out and see if it that helps.
Too high a temperature
it is possible for heat from combustion to cause an engine to overheat quickly depending on where the gasket is blown, but i would look for a lack of coolant circulation first. if your coolant is not getting out of the motor and into the radiator it will overheat very quickly.
Low coolant level, or the cooling fan(s) are not energizing due to a bad fan motor, sensor, or relay- maybe even a broken wire. Engine coolant temperature sensor will cause that everytime... more likely than anything else because it only does it when stuck in traffic or stop sign to stop sign and not on open road.
It will not cause the engine to overheat. You have another problem.
A stuck or incorrectly installed thermostat.
The radiator cooling fan is most likely not working.
Yes it could.
One car can cause it.
No, it would be speculative analysis.
A lot of things could be causing that. First did you check your coolant?
no the higher milage or higher rpms can cause the head bolts to stretch which would cause it to blow
If you have had an extreme overheat in the past. This would most likely cause the censor to melt. Overheat to the point of the steering wheel locking up and the light coming on.
Hey Craig==The most common cause is the cooling fans are not operating correctly. Check them out. GoodluckJoe
Try the rad. fan or the rad. fan relay
low oil low radiatio flued or the thermistat
The overheat of the engine. You could find some information on Wikipedia.
Your motor oil going bad would cause that. That is in the crankcase, not the transmission.
One situation that the overflow jug would cause an overheat condition would be if the hose and/or connectors were plugged up or blocked. NOTE: before disconnecting anything to do with the radiator, ensure the engine is COOL! The cooling system operates under significant pressure.