Hi! My sister has a 2002 Pontiac Sunfire 2.2L. (not ecotec) This week it had started getting quite warm 110-120 Celsius. Today I did a coolant flush and replace thinking it was that, however it is still overheating. Tried switching relays from heater blower for cooling fan, still didn't work. Tried pulling the air temperature sensor (located on air intake hosing from the air box, correct?) to see if the fans would come on, they did not. So my only option left is to test the radiator fan motor. How would you go about doing that?
Also, I read about replacing the engine coolant temp sensor needing to be replaced. However with the fans not coming on, I would assume that its the fan motor, not the ECT.
How about does it over heat? Slow driving thru traffic or idling for long periods of time or high speed traffic?
At low speeds the fan is a suspect, but higher speeds it could be something like the thermostat. But if your fan is my turning one when you pull the ECT then you definitely want to check that fan motor out ASAP.
She says it was overheating while idling - guessing the wind helped keep it cool. when i replaced the coolant it didn't overheat while idling - just regular driving.
Get a block test and check it out.... also i have seen the water pump propellers fail internally and when it is needed under higher rpm the pump would spin but the propeller would slip....
Erik Packard
If the fan isn't kicking on, it's probably the motor if the relay is good. Should have changed the thermostat when you changed the coolant, only a $10 part.
if your low on coolant your fan will not kick on and you will overheat...
^what?
Your fan will kick on before you overheat and I'm sure he has enough sense to use enough coolant.
Update!
I used enough coolant, yes. 9.2L or close to that.
Replaced the thermostat at the same time.
It's not the fan motor as today I used two jumper wires to test the motor again. Works fine.
Read somewhere that there is a fan motor switch somewhere, but also read that this model does not have one.
I am roughly following this page:
http://troubleshootmyvehicle.com/honda/2.2L-2.3L/how-to-test-the-radiator-fan-motor-2#2
Currently I am trying to bypass the radiator motor fan switch, but cannot locate it.
Anybody have an idea of where this is located, or if there is one on this car?
It is also not overheating anymore. Just the fan won't come on.
Update.
Replaced the coolant temperature sensor, fan still does not come on.
Bought a whole new relay, fan still does not come on.
I read somewhere that there is another sensor besides the ECT and the ATS, that by pulling that it will turn the fan on, but can't the page I was reading.
Looking at just replacing the fan motor now, as I was told the fan may run while jumping it, but can still be faulty.
Problem solved!!
As I was saying, she replaced the coolant temperature sensor, however she did not test drive.
After work I double checked everything - as well as resetting the PCM.
Pulled both the PCM fuses (10A) from under the hood, and in the car, as well as unplugged the battery for an hour.
After the hour, I replaced the PCM fuses and connected the battery.
Ran the car for 12mins as described here:
http://www.justanswer.com/pontiac/2bw9v-2002-sunfire-cooling-fan-i-jump-ect-clip-radiator-fan.html
and THE FAN CAME ON!
So, whether it was the ECT, or the reset, we don't know. But it has been solved.
Thank-you guys for your help! Hope this helps someone in the future!!
Daniel
