01 alero fan not working

[tatt4u]

My daughters 01 alero's coolant fan is not running ! ? I tryed new relays no luck, they will come on with the ac and stay on after the ac is turned off, but when the car is parked and turned off the fans shut off and the coolant boils over. I turned the car off and back on after it was hot and the fans started but did not stay on and would not come back on with out the ac

[BNaylor]

Welcome to AF.

How many miles are on this Alero and which engine? If the cooling fans turn on with the A/C then the cooling fans and relays are good or not the issue. With the A/C off the cooling fans are programmed to turn on in low speed at around 220 degree F and 230 degrees F in high.

By boiling over do you mean coolant is coming out the reservoir overflow tube? You may have a bad thermostat if there are no intake or head gasket issues.

[tatt4u]

it's a 2.4, 4 cyl. I've changed the termostat and changed the relays and when it boils over it's after the car is turned off. The fans come on when the a.c. is turned on and will keep running after the a.c. is turned off but when the car is parked and turned off the fans do not keep running to cool the car down and it starts to boil over. The fans will not come on by them self the a.c. has to be turned on to get them going no matter how hot the car is. The temp gauge in the car seems to be working fine.

[sightdev]

Originally Posted by tatt4u

it's a 2.4, 4 cyl. I've changed the termostat and changed the relays and when it boils over it's after the car is turned off. The fans come on when the a.c. is turned on and will keep running after the a.c. is turned off but when the car is parked and turned off the fans do not keep running to cool the car down and it starts to boil over. The fans will not come on by them self the a.c. has to be turned on to get them going no matter how hot the car is. The temp gauge in the car seems to be working fine.

I think "BNaylor" was asking if the water was boiling out of reservoir [overheating] or just "movement" inside. is the vehicle overheating? water movement inside the reservoir is normal and fan not turning on until it pasts mid-point is also normal. In my Alero with 3.4, it is rare the cooling fan will come-on except during the operation of A/C. With cooler weather outside, i would never hear the cooling fan run and it stays near the midpoint marker.

[tatt4u]

it is boiling over after the car is turned off! the fans dont come on no matter how hot the car is, the only time the fans come on is with the ac running! ?

[skeeter123]

I'd check the reservoir cap, it may not be holding pressure. Some auto-parts stores will let you buy a cooling system pressure tester, and give you your money back when you return it. You may have a pressure-leak somewhere; and coolant boils at a lower temp when not under pressure. A new cap can be ~$7.

And even though you said temp gauge is working, it may be worthwhile to check the ETC:

http://www.automotiveforums.com/vbul...d.php?t=660655

Hope this helps.

Quick check:
Make sure that your cooling system is coming up to operating pressure. When cold, squeeze radiator hose to see how it feels with no pressure. Start it up and take it for a drive, till fully warmed up >195deg. (stock thermostat temp). Pull over, and Squeeze the radiator hose, should feel like it's under pressure. No pressure = leak somewhere, and your coolant will boil out (coolant boils at lower temp when not under pressure). Usually it's the coolant reservoir cap that leaks, its supposed to hold up to 15psi. You can get a replacement ~$7 at parts store. Sometimes it's the reservoir itself that won't hold the pressure.

[onepiece]

hi
i have the same problem as urs fans wont come on and coolant boil out of rev......relays and fuses are ok....radiator sensor has been changed...both fans are working when ac on and running at low speed....unplug the radiator sensor fans are running on high speed

after unplug and reconnect the PCM.....fans wont come on when i turn of the ac now and anther thing is that after i unplug the radiator sensor and reconnect it ...the fan wont turn off anymore untill i turn off the car?

really dont know what is wrong? can it be PCM? i dont think the stuck close them will effect fans not on right???

[xeroinfinity]

did this issue get resolved ??

If the test above passed then I would say their is nothing wrong with your cooling system.

The problem could be air in your cooling system.
Has the coolant been changed or ran low right before what appears to be over heating/boiling ??

Cause if its boiling, you probly dont have enough coolant in the system and or its not 100% air tight.
As mentioned above these caps/res arent the best and can leak air, just the tiniest bit can cause problems.