So my top left fan just started rattling.

[glenhentz]

It's not a blatant gear-grinding rattle like I've seen on youtube (although it's more pronounced when i first wake the MBP). I made a Genius appointment for tomorrow, but just out of curiosity, in case they don't have a replacement fan in stock, am I doing anything markedly destructive by continuing to use my MBP with the fan rattling on like this?

As I said, it's not a terrible rattle. Just slightly annoying if anything.

 

[Makosuke]

As long as it's actually still spinning, it's not likely doing damage to anything but itself. Just make sure it doesn't suddenly stop working entirely (although at least in theory, the computer should have hardware that protects it from damage due to overheating in the event of a fan failure).

 

[glenhentz]

Thanks for the advice. Yeah, it's still continuously spinning. I've just noticed not even thirty seconds ago that it's now starting to "sputter". Like, there's the regular, high pitched rattle randomly interrupted by tiny, deeper rattles, almost like it's off balance or something. But yeah, even through this, it's still continuously spinning at normal RPMs.

 

[TheJayWay]

I've had that fan replaced once cause it kinda died and made an annoying buzz saw sound. I took it to my local service provider and they fixed it, but it took a week. It happened again about 2 months ago but I haven't been able to give up my mac for a week so it's still not fixed. I got annoyed about a week after it started doing it again, and opened up the casing and disconnected the fan cable. Problem solved! Now I just run the other fan at a higher speed! I will also have to go back in and re-connect it before I take it in for repair under applecare, otherwise the tech may notice something is amiss and have them void my applecare. Oh well, the things we do!