MacBook Pro Whirring Noise (with video)

[jazzss29]

So I have a 2015 Macbook Pro, and today it has started making a whirring sound which seems to be coming from the top right hand corner of the macbook.

It appears shortly after startup and remains.

Here's a video of the noise: http://tinypic.com/r/2vujz9g/9

Any idea what it could be and how much it may cost to resolve?

Thanks

 

[onVacation]

Sounds like a defective fan.

A new fan costs ~40-50$ I think.
No idea how much Apple charges to replace it, but doing it yourself isn't too hard with the proper tools.