Hi I was a bit premature with my last thread about how quiet my new pump was.....its as noisey as the old one now. I have taken it out and tried it in a bucket and its quiet but the moment it gets in the system ie blocks and radiator the noise is very apparant. Tried flushing out the system with automotive rad flush but no good. Has anyone come across this problem before? My next action is to get more tubing and try different arrangements. Bit stuck now for a soultion.