Got called in to daughter's problems with a her Whirlpool dishwasher. Rollabout unit with hose that attaches to kitchen faucet. Complaint was that it was draining slowly. Had repairman out and for a hefty fee he monkeyed around, and blew out drain hose with air compressor. Worked better for awhile, and now back to a slow flow, slightly more than a dribble. Have checked and cleared the drain hose, with compressed air, and a wire probe. no visible obstructions. Blowing into it by mouth shows no obstructions either. Pump motor is clean, had it out and it turns over OK, impeller clean, as are passage ways. Turning over the impeller, there is one part of the rotation where the motor feels like passing through a magnetic field. one per revolution. Wondering if this is normal, or should there be more than one field the impeller has to turn through? Should I be looking to replace drain motor, or are there other issues I need to address first? Replacement is a 5 minute job and $65.