Is the impeller making noise or the motor?
Do you run it year round or seasonally?
Check the cord for any damage. Mice will chew the insulation during the winter months if given a chance. My father-in-law had to replace a pump last year that mice chewed on the power cord of. If you do have to replace it, I would do another Aquascape or NurseryPro pump. They have 3 year warranties and you might be able to take the old one and return it in the new box. That would give you 2 new pumps and have a new one on backup at all times. Not advocating fraud, but Aquascapes is really good about returns on there equipment and keeping customers happy.
