Loud i5 stock cooler and low temperature.

[IKubi1]

Intel i5 2500K

Motherboard: B75A-G43

Stock cooler

At the begining everything is fine and quiet. After some time of non-stresfull work the fan starts to be very loud. Suspending stops the cooler, but it's laud again after a resume. The tempereture is around 40 C. I've tried to manually limit the fan frequency in my BIOS, but even when the frequency dropped from 2000Hz to around 1000Hz the noise didn't change. There are no wires or any other things that could have caused it. May it be some kind of malfunction?

[Jose_H_Intel1]

You may clean the fan with a compressed air can. Otherwise I assume the bearings are causing the noise; in such case you can contact http://www.intel.com/p/en_US/support/contactsupport Intel support for a fan replacement.