It's coming from one of the two fans on the CPU liquid cooler.
Is this something I need to replace asap? There are two fans blowing air out if it's only one is it a must replace or can it wait for a bit?
hope you read this before you buy the can of air , they are called air duster and can be got from a certain electronics retailer that begin with the letter m ( note to editor i did not advertise).
WARNING only hold the can vertical because if you turn it sideways the propellant squirts out. Also , do it in short bursts because the can will very quickly become cold and burn your fingers . There are many different cans so make sure you get cold not warm air ... no that is not a joke you can buy hot or cold air.
Clean the filters > Clean the fan's blades > Take the cover off the Fan Motor's Spindle and put a drip of "thin" oil on it > I'm told that "3in1" is thin enough, but wait a while for someone else to confirm this