What Makes a Pump Noisy?

[pjhaddock]

So I was thinking and maybe there is stuff about them I don't understand. You have a pump, say Bubble Blaster HY-3000. If you plug a pump in with no impeller in it it's dead silent since nothing is happening. With an impeller it makes noise. So is the only place noise can come from is the impeller? Mine has gotten much louder (I take it apart and clean it a few time a year) and I'm trying to figure out if a new impeller and ceramic bushing would fix it or is it possible for the motor itself to somehow make noise only when an impeller is in it?

Same thing with a Reeflo Dart. Mine is about 11 years old. I've replaced the bearings twice over the years. This last time there is still a good bit of noise coming from the pump (back of it) that didn't go away but it's not the bearings. Running dry or with water. Is there something in the pump that would make noise other than the bearings and impeller when running? It's also completely silent when the guts out of it.

I've always wondered this stuff. Thanks for any knowledge some of you may have.

 

[zsuman101]

If it says... made in china, it's noisy

 

[ca1ore]

Let's see .... motor hum, transmitted vibrations and impeller noise. The magnets can swell over time and make noise.

 

[mcgyvr]

The impeller (magnet+prop) is the ONLY moving part in a pump..

As stated the magnets can/do swell causing more friction on the inner walls..
Deposits build up on the inner surfaces too and cause more friction,etc...
The bushings can be worn..

A good cleaning can help..
But a replacement impeller and or bushings would be the only fix if the magnet has become larger or bushings have worn..

A prop cutting through water creates noise too obviously..

But without the impeller there is nothing moving hence no noise..

 

[mcgyvr]

If it says... made in china, it's noisy

Not always true... but in general...
lower cost = less precision + lower quality materials = potential for more noise..

 

[Fcsteve777]

Could be buildup in the bore that the magnet runs in, Damage to the impeller or buildup, or wear in the impeller bearings most likely. Also watch out for transmitted noise if you dont have soft piping on either side of the pump.