My Book Studio FW800 makes constant clicking noise when idle

WD External Drives External Drives for Mac
4

I’m not tech support but it seem like the My Book is beginning to show signs of failure, if possible backup all of your important files. I recommend you to contact tech support directly by email or phone, they can answer any questions you may have. Follow the link below. 

http://support.wdc.com/contact/contact.asp?lang=en