Question Cooler working normally and abnormally fast(and loud) at random

[JukusMaximus]

So i've noticed that my cooler has been acting up lately. Thing is: sometimes, it works completely silently (as it normally does), and if my laptop gets heated it does make a slightly louder sound, nothing too loud (once again, expected behavior), even when I play graphically demanding games/use demanding programs; but at times it starts buzzing quite loudly and I can't figure out what is causing this, I've used compressed air to clean it (however, I didn't open my laptop completely ) but once again, cooler works normally at times, and just goes crazy at what seems like somewhat random pattern. It does happen usually when I play games, but even when it got a bit heated before the issue at hand it wouldn't be this loud. At times even causing vibrations to my whole desk...
I'm thinking it may be caused by some kind of malware or simply because it's lifetime is running out. But by all means, if you have anything on this, please help.
Let me get one more thing clear: when it starts buzzing my PC isn't necessarily heated in the slightest, so it's not just trying to keep up with the temperature as one may suggest.
I did recently used Malwarebytes and Avast to clear my PC, but it didn't resolve the problem. I also noticed that it usually happens in the evening (I do use my PC quite a lot during the day, BUT, I did experiment with turning my PC off and leaving it for a while in the afternoon/evening, couple of hours or so (enough for the PC to completely cool down), but it didn't really do anything. I know this part sounds stupid, and makes no sense to me whatsoever, but I've noticed that the buzzing usually happens late in the evening (approximately around 11hours PM-midnight)

 

[Eximo]

The fan could just be going bad. How old is the system?

Go ahead and disassemble to the point of taking out the fan. Make sure nothing is in there and that there aren't broken blades or anything. Spin it by hand to see if it is smooth. If it catches inconsistently, probably got dust or dirt in the bearing. Pretty much means the fan needs replaced.

 

[JukusMaximus]

Sorry about the late reply, I got a lot of things going on. So, I recently reinstalled the system, I'm gonna reinstall any drivers I find suspicious, as for opening my laptop, I am too afraid to do it on my own, because I didn't really find appropriate tutorials online, I don't think it's about the cooler itself, as in hardware, because sometimes it works completely normally (for an example, as I write this). But sure, if I find someone who can open it for me, I guess we'll see what's inside.