Cooling fan makes a noise

the bearings

It can be worn out fan belt or the fan is got dried up and needs lubrication.Inspect fan belt.
Check the help link mentioned below:----

Engine makes noise and Cooling Fan belt Breaks?
http://howtobyme.blogspot.com/2011/12/engine-makes-noise-and-cooling-fan-belt.html
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I would power the server off. Blow it out with a can of air. Power it back up.. If it is still making a noise, you need to replace the fan.

fans tend to make loud noise right before they stop working!!! check to make sure that there is no clump of dust inside affecting the spin of the blades

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/charles_c2f37a3461344482

1. Could be a caught foreign object between A/C (air conditioning) fan and cooling radiator, producing this loud noise.
2. Could be a damaged fan blade, mowing the cooling radiator.
3. Could be a loud noise comming from the fan's electrical motor.
4. Could be a broken off fin (small wing) of the cooling radiator, striking the A/C fan, producing this loud noise.

fan loose or bearings going

check the plastic rings behind the fan blades, check to make sure plastic rings is tight and the screws holding fan cage on. Then when putting the fan cage back together, make sure it is tight so it wont vibrate

A bearing more than likely has went bad causing your fan to stop properly cooling your unit. Replace with a compatible fan and you should be all set. Hope this helps.

yes need to replace

The CPU wont make noise unless its frying. So its either your hard drives, cd drives, or your fans.
If its your fans i sugest buying newer "Cool Master" fans that are powerful but less noisy