Question Rear Fan Issue

[Baawuu]

Hello, I have a Lian Li LANCOOL 215, and I'm facing an issue with the rear fan. Sometimes, it runs slowly and makes a disturbing noise, and it stays like this for hours. Then suddenly, it speeds up, and the noise goes away, but after a while, the problem comes back intermittently. I have attached an illustrative image to show which fan I am referring to.
Image link:

https://imgur.com/Uy6vtcd

View: https://i.imgur.com/Uy6vtcd.png

 

[JohnBonhamsGhost]

it runs slowly and makes a disturbing noise

fan's bearings are known to fail and cause issue like what you're facing.
there is really no way to fix them, can't just oil them like other types of bearings.

just get a nice 140mm to replace it.