Cpu makes a grinding sound when thinking, not fan or hdd

[dragoon7201]

Hi all,
I just built a new computer with the following components
CPU: i7 6700k
FAN: CoolerMaster HYPER T2
MB: ASRock z170 pro4
RAM: 2x8Gb Crucial DDR4
Storage: Adata 240Gb SSD
PSU: EVEA SuperNova 650 G2
GPU: none atm / using integrated intel 530

When opening a new webpage or whatever, I can hear a faint grinding sound that sounds like a hard drive spinning except I don't have a hard drive installed. It comes from the cpu and is not the cooler fan, as I have stopped it physically and can still hear the sound. All components are spank new, I am wondering what might have caused the noise and whether it is something i should worry about or if it would just go away?

Update, all case fans and cpu fan are disconnected, sound is 1000% coming from cpu or motherboard. I know there are no moving parts, which is what confuses me as to what is making that sound.

 

[kaptainkuftic]

Hah, uhh, what?

Maybe it's a fan on the top of your case? There aren't any moving parts in a CPU.

 

[juannfox]

Also when you stop a fan, it's engine is still running, hence it can make noise. Don't discard it being the cause unless you unplug it mate