Vario D5, louder as it gets slower...

[Mellowyellow]

I bought a T3 with a vario D5, but when I start to turn it down it will get louder (high pitch) with a lot of vibration. At level 1 there isnt much high pitch but a lot of vibration, lvl 2 more high pitch little less vibration, lvl 3 a lot of high pitch lots of vibration, lvl 4 less high pitch than any other setting,medium amount of vibration (my setting since it is the quietest), lvl 5 tons and tons of vibration, medium amount of high pitch.
I noticed a little squeal when hand turning the pump when not installed, but thought it would go away once it had liquid running through it.
Is this all normal or did I get a rotten apple?
thanks

[Diverge]

Originally Posted by Mellowyellow

I bought a T3 with a vario D5, but when I start to turn it down it will get louder (high pitch) with a lot of vibration. At level 1 there isnt much high pitch but a lot of vibration, lvl 2 more high pitch little less vibration, lvl 3 a lot of high pitch lots of vibration, lvl 4 less high pitch than any other setting,medium amount of vibration (my setting since it is the quietest), lvl 5 tons and tons of vibration, medium amount of high pitch.
I noticed a little squeal when hand turning the pump when not installed, but thought it would go away once it had liquid running through it.
Is this all normal or did I get a rotten apple?
thanks

My pump does the same thing. Certain RPM's are more noisy then others. I gotta find a better way to dampen the vibrations from the T3 when the pump is running slower then setting 5.

[alacheesu]

Resonance, maybe? Anyway, vibrations should go away if you soft-mount it.

[mindwreck]

my pump does the same too. Its over 4 years old but it still does it. The quietest setting on my pump is 4. on 5 its the noise from the water and whirling noise. I put some sound dampening material under it and its silent more than 2ft away.