Brand new MacBook Pro making strange buzzing/grinding noises???

Hi all,

I just received the latest MacBook Pro 15" for my birthday. I'm not quite sure on the specs and such, but rest assured it is the current model offered by Apple.

Anyways, it worked like a charm for the first two or three weeks, and then suddenly it began emitting strange buzzing/grinding noises. These noises are best described like the ones that occur when a laptop is bumped while a CD or DVD is spinning in the disc drive, but the ones I'm experiencing are much louder and longer. It's like a little airplane is taking off inside the computer! Needless to say I'm quite worried whether or not something is wrong. Can anyone offer advice??? Thanks in advance.