engine cooling fan 2001 silverado

Hi
I have a 2001 silverado 5.3 that I was having problems with the heat not working very well. I brought it in and had the thermostat replaced and that worked. I went up to the lake icefishing it was like 10 below zero and the heat was working fine. when i got home i noticed a loping noise somewhere around the front of the engine i think it might be apulley or something. I recently replaced the serpentine belt. this morning when i got up i went and started it. its like 20 below zero. I let it warm up and went out and noticed the engine fan was running and the truck was not yet up to heat. at 20 below i wouldnt think the fan should even come on so i took it for a drive and the temp gauge fell a little so i opened the hood and the fan was still running. and that noise was still there any idea on what this could be and why the fan would be running?

thanks
garys:runaround:

Hi
I have a 2001 silverado 5.3 that I was having problems with the heat not working very well. I brought it in and had the thermostat replaced and that worked. I went up to the lake icefishing it was like 10 below zero and the heat was working fine. when i got home i noticed a loping noise somewhere around the front of the engine i think it might be apulley or something. I recently replaced the serpentine belt. this morning when i got up i went and started it. its like 20 below zero. I let it warm up and went out and noticed the engine fan was running and the truck was not yet up to heat. at 20 below i wouldnt think the fan should even come on so i took it for a drive and the temp gauge fell a little so i opened the hood and the fan was still running. and that noise was still there any idea on what this could be and why the fan would be running?

thanks
garys:runaround:

if you have electric fans the ECT reports the engine temp to the computer/pcm...this then will command the fan to come on if it reports that the engine is too hot..the ECT is most likely defective or the connector is corroded/wires etc....this could have occured when the thermostat was replaced..

this might be a dumb question but what is the etc? is that the tempature sensor? if not where is it?
thanks
garys

and if it is the temp sensor is there any way to check it without buying a new one?

and if it is the temp sensor is there any way to check it without buying a new one?


ECT engine coolant temperature...measure resistance then compare to the resistance / temperture chart for correct reading..

at 40deg f R= 7300 ohms at 0deg f R=23,ooo ohms..

at 190deg f R= 245 ohms...

I think GM 2001 year model trucks all have mechanical radiator fans?

If I were you I would look at replacing the radiator fan clutch. The fan clutch should engage when the truck is first started...it will then disengage in a few min as the truck warms up..... then it will operate as required, depending on the temp.

If this is a 2001 it does not have a electric fan clutch. It is normal for fan to spin full speed when first started up. Until fuild in clutch disapates. The cooler it is the longer it will take. Then when clutch get hot it will reingauge.

http://i941.photobucket.com/albums/ad260/autotech234/PMX0705Satmec001a_large.jpg

http://i941.photobucket.com/albums/ad260/autotech234/PMX0705SATMEC009_SM.jpg
A broken or weakened thermostatic spring in the clutch hub cannot be replaced or repaired.




http://i941.photobucket.com/albums/ad260/autotech234/PMX0705SATMEC005_SM.jpg

Silicone fluid oozing past the bearing seal means the clutch must be replaced.


If your truck is like most, the cooling fan is mounted to its drive pulley via a clutch. Clutch fans operate at different speeds under different conditions to help reduce drain on the engine and to save fuel. When the engine is hot, the clutch fan runs nearly as fast as the engine. When the engine is cold, the fan runs much more slowly.

The fan clutch operation is regulated by a valve that is opened and closed by a thermostatic spring. The valve controls the flow of a viscous silicone fluid between chambers in the clutch assembly. When the engine is cold, the clutch is essentially disengaged, which is why the fan runs at its slowest compared to the engine's speed. As the engine warms up, the air flowing to the fan assembly becomes hotter. The hotter air causes the thermostatic spring to unwind and open the valve. Silicone fluid from the reservoir chamber flows into the main chamber, engaging the clutch, and the fan spins faster (though it's still slightly slower than the engine).

Hope this helps

I think GM 2001 year model trucks all have mechanical radiator fans?

If I were you I would look at replacing the radiator fan clutch. The fan clutch should engage when the truck is first started...it will then disengage in a few min as the truck warms up..... then it will operate as required, depending on the temp.

he never answered my question " electric fans ?"....
this model vehicle does not come equipt with electric fans........BUT there are some who have changed this..

can he not know that the fan will always rotate with the fan clutch ?
I believe it is possible...

since it was below zero out he may have lost heat because he was low on coolant or it froze...this is very common...