My macbook pro is making a weird sound, please help?

Question

Hello,
i have an early 2011 model, it was running soo fine until now.
its making a weird sound, to describe, it sounds like a small *trrr* at normal state, and at high, intense states, (playing games..) it turns into a loud *trrrrrr*, but, if i hit it gently over the keyboard, it goes away, then comes back.
please, i dont have an apple retail store in my country, i need help from here, help me.

Answer 1

first thing to do is to buy a new hard drive and an external drive before it fails so you won't lose your files.
once you've done that, put the new hard drive in the external drive and open disk utility.
format/erase your new hard drive as MAC OS EXTENDED Journaled.
After that has been done, open carbon copy (if you don't have it, you can download it for free).
Once carbon copy is open, click on clone your hard drive.  Source drive is what you're using now and your target drive is your new hard drive.
Once carbon copy is done, turn off your macbook, open the back of your macbook, take off the hard drive and install your new hard drive.
After you've done all those, turn your macbook back on and you're back in business.