MOBO Fan Issue

I have this motherboard (Link) and just recently it has started making a odd noise, sometimes it happens sometimes it doesn't it almost sounds like its rubbing on something but I've checked and started it without my video card in and watched it as it was running its not rubbing on anything but this noise bugs me very much its a like higher pitch noise compared to all my other fans and was wondering if I could slow down the speed of the fan to get rid of this, I noticed if I held my finger on the fan just slightly to slow it down a tad bit, the noise stops, Now I tried using speed fan but none of the controls work with this fan, and the fan is hooked up just like any mobo controlled fan as you can see in the link. Anyone got any ideas? Or if worse comes to worse would unplugging this fan cause any damage? =/

Which particular cooling fan? Try this link http://www.techrepublic.com/article/quiet-noisy-computer-fans-with-a-drop-of-oil/5034842

Which kind of fan are you referring to? is it the case fan/chassis fan?

Depending on the quality of the case fan, some produce more noise than others. Overtime these fans degrade so it is a good idea to replace them with a new one with the right dimensions in order for it to fit in your case. I'd also advise not to control anything using the speed fan program unless you know what you are doing. If you unplug the case fan, then (assuming you only have one in your case) there will be no fan to deal with the accumulated heat inside it. Internal components begin to pile up heat hence, would cause damage to hardware over time and depending on your BIOS settings, will force your computer to shut down once it reaches a certain high temperature level.