MacBook buzzing noise

Hi everyone,
For the last two days I had a few issues with my standard Macbook, it wouldn't start up, then I had a grey screen for a few hours, then a blue screen. I re-installed os x a few times and eventually it worked with an erase and install. Everythings working perfectly again now, but the machine is considerably louder than it used to be, there's an almost constant low buzzing sound. Has anyone else experienced this?
Thanks

What you describe could be related to hard drive problems. Make a backup of your hard drive as soon as you can in case it is failing. The low buzzing sound could be the fan or the hard drive, it's hard to say.

How old is the machine and is it still under warranty? You might want to have it checked out by an authorized Apple repair shop or at a local Apple store.

Regards.

I don't know if this helps, but a computer at my school kept randomly making a loud buzzing. Apparently it was the fan or sound card.

I agree with above, whether or not your hard drive is failing, I would back up too incase its something worse.

I think it's still under the three year apple care. Luckily I backed up everything last week before this happened so I didn't lose too much. I'll take it to an Apple store asap though, thanks!

Now it's started getting REALLY hot

uh oh...

I'm experiencing the same ordeal, I have to levels of buzzing though. I think it's the fan. I need to take mine in as well but I depend on my comp everyday....