My rear case fan sometimes slows down hugely and makes a lot of noise

Ricklapleck

Reputable
Jul 30, 2014
2
0
4,510
Not all the time does this happen but sometimes when I turn my computer on my fan starts off normally and fast and then it slows down massively and very rarely will the problem fix its self and stays very noisy its so slow I can follow it with my finger and generally speaking it stays like this no matter what I do or how hot my computer gets although rarely it does fix it self.
I have not overclocked my pc and I use it for gaming and I did take it in for diagnostics because of this issue and the guy said he couldn't find any faults and afterward the fan acted fine however its doing it again and I have no idea why this is a fairly recent issue there also shouldn't be any wires in the way as the the diagnostic guy probably would have said that was an issue I think.
So what is this.
 


Is the fan hooked to a mobo fan header or a case fan lead? How old is it? It sounds like it has reached the end of its useful life, but it could be something else. Try it with a different lead or mobo header - if it does the same thing, it probably needs to be replaced.