What is wrong with this fan

[Merchant1]

This fan is extremely loud, even more so when the case is closed. It is always making this noise, even during boot up and while not running any applications. https://youtu.be/qtaf87Pl-Fs

 

[Someone Somewhere]

Sounds like it's either unbalanced or rubbing on something.

 

[kango69]

Strip down the fan and clean it.
https://www.youtube.com/watch?v=1lxvmay2tn0