Posible faulty WD RED drive?

Ok odd one here, I bought 4 drives to run in a raid set.

One of the drives is making a buzzing like noise which I can only assume must be the motor?

The drive works fine and is passing the diagnostic tests (running extended test now).

Going to try and get a RMA for it tomorrow but thought I should post here first, see if anyone else has had this problem.

Hi and welcome to the WD community. See if some of the links below are useful to you.

How to tell if the noise or sound the drive is making is normal

http://wdc.custhelp.com/app/answers/detail/a_id/568

Difference between Desktop edition (WD Blue, WD Green and WD Black) and RAID (Enterprise) edition drives

http://wdc.custhelp.com/app/answers/detail/a_id/1397