[YankeesPwnMets]

So, I did something pretty stupid today.... the controller USB cable, which was still attached to the PS3, got stuck into the wheel of my chair. Not knowing, I moved the chair which made the PS3 fall about 3 feet to the ground. The hard drive and components seem to be fine, but it makes this weird rattle noise whenever its reading a game disc.

Any clue into what this is?

[vertical limit]

Maybe the guts of the Blu Ray drive are out of place.

[YankeesPwnMets]

I shook it around gently and the noise stopped.....

maybe some parts were out of place..

[Wolf68k]

Part of me wants to tell you to open it up, find out what broke and fix it. At the same time since you magically "fixed" it and it's still working fine then I say let well enough alone.
There are plenty of guides on how to open up a PS3 if you're at all interested. iFixIt.com is my first go-to place http://www.ifixit.com/Device/Sony_Game_Console

[Slamman]

The PS3 is a cinch to open compared to Xbox360s, so if you are feeling inclined, it's rather easy. One thing to note about the PS3 ODD, the taped down or glued down plastic that keeps the disc dust door in play, that can easily come undone, and it can account for some serious loading issues, I think it's the major weak point in these designs, but also loading as it does, via tensioners is always tricky to service, they typically replace that mechanism as a whole, so you have three main parts components, the loading tray itself, laser diode pickup assembly, and the subassembly logic board mounting underneath it all