Little giant pump psm-006 noisy while running, why?

Are you running these pumps full-time, even if they're dry? If you are, that's far beyond their design. The sink should drain into a sump or cistern, then the pump should empty the cistern on demand from a float switch.

I don't know of any pump except possibly a bellows-type bilge pump, that can be expected to run full-time, even when dry.

If the pump starts after cooling down, and then starts again, it has a thermal overload in the motor, so you should pull it out and see if for some reason the impellers are stuck.... could be an easy fix.

it has to be connect

Frank the pump goes inside the box with the foam around it.

the floats are mechanical on these pumps, unlike the electronic ones on other models , the floats can get stuck on them most common reason is forign object stuck up inside area of float (leaves, tree droppings etc)

It sounds like the float assembly is getting restricted somehow. Check to see if it is hitting the cover and/or binding over normal up/down travel.

You can try to force prime with a garden hose. Put the hose in ether side suction or discharge.

You might have 2 problems. The GFIC might be wired wrong or the pump wirng might be compromised with moisture. The noise issue? Are you running this unit without submersing it? They will burn out if you do. To get a more accurate running sound, submerse it with a flexible pipe so you can run it in a 5 gal bucket without losing the water.
It's possible a bearing is burned out.
Ron

Nope, not a good thing

Hi Tom (and Lindsay?),

Ok lets get a little more info,

1. Plugged in? (Have to ask)
   
2. Does it run and not pump?
3. Does not run?
4. Tried moving the float switch?
5. Pull the pump and see if the intakes are clogged

Please comment back with your findings
Mike