I was doubting myself all night that I should have heard the noise with the belt off. So I've took it off again today, i'm getting MUCH quicker at doing it, and took another video for your viewing pleasure. It definitely sounds very different without the aux belt on. I've gave it a few revs in this one, not too much since it doesn't have the torque bar fitted to the mount. So I am not sure whether the load of the alternator and the turned off air con, would be enough to make it so loud.