I have this loud noise coming from my engine bay. The noise has been there since I bought the car a few months ago. Any ideas of what it could be? Here is a video of the sound. I can't begin to explain the noise so hopefully you can tell what noise it is just by watching the video. Any help at all would be greatly appreciated.

Noise, Help? - YouTube

 

I assume you mean that high pitched sound? You need to be more specific, that video's sound is not obvious about the sound you are referring to.

Assuming it is, I would check your belt tensioner, or possibly a pulley bearing is bad, or more likely the alternator bearing is tired.

 

I agree. I was expecting a hammering sound but only heard a bearing screech. Tensioner pulley is candidate #1 and alternator is #2.

 

I would be more specific but I don't know how I would describe the sound, All I can say is that it was the loudest sound in the video. But from what you guys heard you think it is a pully? I hope its not the alternator because that is fairly new. Thank you guys for your response.