Sounds like water has leaked from the pump and has gotten into the motors top bearing.
Take the pump off the top of the motor (not a difficult job) and check the top of the motor for water damage.
Water damage to the motors top bearing (rust), will cause the noise.
There is a very good chance your pump is leaking (this will happen if the machine is not used much).
You might be up for a new pump, $200.00 to $250.00.
Oil the bearing of the motor and run it without the pump connected.
If the noise is still there, you might also need a new motor, up to $300.00.
Rotary pumps, if not used a lot can leak through the shaft seal.
If you replace the pump, make sure you fill the space where the pump and motor join with grease, this will stop any problems with the motor in the event of the new pump developing a leak.