I have a 2001 Chevy express, and it makes a loud fan noise when I turn it on, but goes away after a…

I have a 2001 Chevy express, and it makes a loud fan noise when I turn it on, but goes away after a while of driving. What could it possibly be?

if it has a mechanical fan blade, that assembly needs replacing, it's wearing out inside. Or, if it doesn't overheat, live with the noise, those units are not cheap for oem reliable ones

false