I went outside and when I came back I turned on my computer, and it sounded like a damn power drill. Actually thought that was what it was at first for a few seconds. Hot damn.
Immediately shut it off and went out again to buy some compressed air and cleaned the thing out thoroughly. It hadn't been cleaned in like a year and a half so it was covered with dust inside.
Fans all sound smooth as butter now though, praise the machine spirits
Also cleaned my keybaord. Thankfully I don't get a bunch of food/crumbs/soda/jizz in there so it was like new with just a couple of passes with the air.