KitchenAid KDTM704 dishwasher makes grinding, humming, knocking or squealing noises

The checks in more detail

A rattle, a knock or a drone that stands out has a cause you can often find in a few minutes. Look at the load first. A cup tipped over, a utensil dropped through the third rack, a loose lid or a pan handle poking through the rack can strike the spray arms or the tub. Pause the cycle and look. The FreeFlex third rack can slip out of its track if it is not pushed fully home; check that it is seated and that nothing sits over the edge.

Spin the arms by hand to check that they clear every dish, since an arm that clacks against a tall item makes a rhythmic knock. Check the racks' wheels, because a worn wheel rattles as the rack slides. If the noise is mechanical, it may be debris in the sump, which makes the pump grind; remove and clean the filter, check the sump for glass or a bone, and refit the filter.

A hum with no water movement can be a blocked drain pump or a failing pump, and a drone that grows when the dishwasher heats can be the fan or the element in the drying phase. A dishwasher that is not level, or that is loose in its cabinet, amplifies noise, so check the front feet and the mounting screws. If the noise continues with an empty tub, note when it happens, and quote KDTM704KPS and the serial number from the label when you call KitchenAid.