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Cooling Fans wont turn on until at like 235F

J

jhnnyboz

New member
Hey i was wondering why my radiator cooling fans are not coming on until the temperature reaches about 235-245. I changed out the thermostat, radiator cap and made sure there is enough coolant. They run all the time when I have the AC on so the fans work fine but it seems like there is a thermostatic switch or something that isnt telling the fans to come on at the right temp.
I have a 97 grand prix with the 3.1 L. Please someone explain this to me and also let me know where that thermostatic switch is if there is one.

Also do these fans have 2 speeds or just 1 speed.
 


Put in a cooler T-Stat and have the PCM tuned with lower turn on points set that way they stay on longer ;)

Sure there isn't air in the system either?
 
Hey the factory thermostat is set to open at 195F so this car should run fine with that thermostat in, i will bleed the system and see if that helps, so there is no thermostatic switch?? the fans come on and then turn off at like 200F so they stay on pretty long. i was gonna just run a switch to the fans to turn them on manually but one fan runs of 8Volts and the other fan runs off 6 volts, so ill have to get two variable resistors because ill be using power from the battery. this just seems like i am not fixing the original problem tho. So tell me this... what switch or sensor tells the fans that the temperature is 235F and to start running????
 
ok i just wanna make sure i am bleeding the system right... i just drive the car until the thermostat opens then open the bleed screws until i just see coolant coming out then close them. i opened the one on the thermostat housing first then the other one. so i did this and there was no air bubbles coming out at all just coolant. i even did it with the car idling so unless i am doing this wrong there is no air in the cooling system
 


try taking the cap off the rad and start the car and let run for a while but not long enough to let the stat open
 
ok so is there a possibility of the problem being the Coolant temp sensor. Because I thought that if that was bad then it would throw a code and the SES light would come on. But there is no SES light telling me this, so i just dont want to go out and buy a 20$ sensor when that is not the problem. Also the temp gauge in the dash seems to be workin right because i can tell the thermostat opens at about 195 like its suppose to so if the coolant temp sensor was bad woulding it be causing a different reading in the dash to since they run off the same resistor
 
if it was bad there would be a code and you could check it if you had a scanner had reads pins, but if that was bad it would show that the sensor would read -40 all the time(ircc)
 


ok so your telling me that the cooling fans are suppose to come on like 2 notches away from the red, i doubt that, every other car i have driven and rode in the temp gauge stays right in the middle, but on my gay ass car it moves up and down constantly
 
do you install your stat upside down...
and yes ive seen it done
and why make two threads whynot just add the this one?
 
If it moves up and down constantly that sounds like an air pocket/bubble that is moving around and can't get past the T-Stat so its fluctuating the temps.
 
Nope thermastat is installed right, and I bled the cooling system like 5 times and there are no air pockets at all in there. So when I went to change the coolant temp sensor the old sensor was cracked and that might have been why the fans werent coming on but the new sensor just reads hot all the time, even after getting another one, what the hell
 
K just put the other sensor back on and it is readin accurate again, t stat opens at 195 and cooling fans come on at like 220,(the reason they were coming on late before was because the placistic part of the sensor was cracked n it wasn't making a good connection, now I have the 3 prongs plugged right in without ne plastic) Do not buy the cheapest engine coolant temp sensor from advanc, I went through two of them and neither one is calibrated correctly or something because even before the t stat would open it was already reading 250, so do not buy it, it's ****ing junk
 


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