Question Super loud, kinda rattly sounding fan (audio linked) Acer nitro 5

[elvalight]

https://streamable.com/ntt5ok
It's been going on the past week... it started out where it'd make this sound for maybe 10 mins, then stop the rest of the day. It's gotten progressively longer each time, to the point where it's been 24 hours of this nonstop. I called a computer repair place and sent the audio file and the guy said it sounded unfamiliar and that I should just replace it. It works fine aside from this so that's out of the question, plus I do not have the money for that. I know it has to be something small...
I added new thermal paste maybe a month ago but the noise didn't start till last week as I said. Not sure if that's important. I watched a video and followed all the steps to a T so?? Also it's 2 years old, just out of warranty (of course)

 

[Mihai Baiasu]

The noise might be caused by the bearing inside the fan. You could try lubricating the fan bearing with sewing machine oil (only a drop or two, not too much!).
Also, you should check the fan blades so that they're not damaged in any way and that they do not touch anything.

 

[Paperdoc]

Do NOT try to add more oil to your fan. That could be done over 2 decades ago with a different fan design that you could open up to oil bearings and then re-assemble. You cannot do that with today's fans. To open them you break them! And squirting oil inside a closed case means you put oil everywhere inside the fan making a mess that will cause more rapid failure.

What you describe is typical of the early stages of fan bearing failure. As time goes on the period of initial noise before going quiet will lengthen until it makes noise almost always. THEN comes complete seizure of the fan so it cannot run. The ONLY solution is to replace the fan. You may not need to do it now - that fan may last a year or more before seizure. But plan to replace it, and set aside a bit of money.