Originally Posted by viper522
My 920 just started the marble crunching sound at all speeds above idle. hrmph
Hey Viper, I ran into a similar issue when I refilled my 920 loop. The pumps on these systems are very weak so any amount of air trapped in the pump/block assembly will just sit there until it is worked out of there. If you can, I would recommend taking the unit out of your system, hook it up to an external PSU, and power it on/off and move the rad/pump all around until it works the air out of the pump. I had to alternate moving the rad over the pump and vice versa to work my air bubbles out (had to shake the pump a bit too...cursing at it sometimes helps also!
Otherwise, try moving your case around with the pump running (gently so you don't damage any components) to try to work it through. Once the air pocket breaks free the pump should be much quieter. Good luck and hope this helps!