The fan on my laptop is making a growling sound.

[tpress]

My fan started making a growling noise about a week ago. It is still blowing air but I found the noise very disconcerting. It is a grumbling sound that is not necessarily constant. It kind of goes up and down in tone. I was concerned that this meant that the fan had broken and when I called a repair shop they said it sounded like the fan was dying and that I should take it in to get it repaired/replaced before something more important like the motherboard overheated. When I took it in, the shop could not find anything wrong with it. Other than having an annoying sound it did not appear to be broken at all. They said the best they could do was replace the fan but it was still working and they couldn't tell if it would break anytime soon. Should I be worried about this sound? What is happening?

[WAWood]

@tpress 

Fans have bearings and those wear out.  It can be gradual, or it can be sudden.  If the fan is making noises, then you need to replace it, otherwise, it could go out suddenly and the overheating could damage the laptop.