I bought PS4 Pro like many others today, and from the first startup my PS4 Pro started making very loud "click" sounds. It comes clearly from middle section of the left side of console (or up if you have it vertical). The sound repeats 1-3 times in a minute once in while, and it almost hurts my ears if I am close to console. It reminds like you hit glass with something metal, or you brake very hard plastic. I did not hear any sounds when I was playing games or watching movie, only in main menu these sounds appear. It doesn't matter if there is disc inside or not, but i think it is related to disc drive.
My two other friends bought PS4 Pro too, and they have not heard anything like that. Should I be worried and go ask about it from the store where I bought console, or just wait and listen if the sound goes away in like a week or two?