What would make this sound?

[andrewwynn]

Turn off car and spin the fan by hand. If the engine is cold it should turn quite easily. If the fan clutch is locked you risk sending the blades though anything in their path usually coolant hoses and reservoir. I've seen dents from the bottom of the hood. If it doesn't spin easy remove the fan before it self destructs. If you are in the northern hemisphere writer started two days ago you can lesve it out while waiting on a new clutch.

https://youtu.be/lozXFFwfok8?si=miNsPN7dS3hGjqhE

This usually works to remove the fan but learn from my mistake; let the pressure/vacuum out of the coolant reservoir first and put a rag over the upper hose. I broke my thermostat in half once when the upper hose was stiff due to being cold and under vacuum.