If the fan is causing the noise you could if you are mechanically savy remove the fan, peel back the label on the fan and add a couple of drops of light machine oil (such as for sewing machines) to loosen up the fan bearings. Do not use WD40 etc.
Computer must be shut down when you try this, take note of the orientation of the fan blades. If not you will need a new fan or cooler assemble. I have repaired the fan on my several years old chat rig successfully.
Never operate a machine without the heatsink and fan in place or you will let out the magic smoke.