Question PC case fan grinding sound

[Chezzy]

I have a no-brand 80mm fan in my case. Often whenever I turn on my pc, it makes grinding noise and it spins slower than it should be. And whenever that happens, I grab the spinning fan and pull it back and fourth just a little bit and it works normally again. Is the issue in the motor inside the fan? Should I upgrade to a better case with 120mm fan?

 

[Paperdoc]

If this system and fan is a few years old, that fan's bearings may be wearing out. Plan to replace it soon. You don't need a whole case. Replace with another of the same size if you have to, but see if there is space for a larger one like 120 mm.