If you hear the noise during the wash cycle, you will need to replace the pump assembly. The whole unit gets changed together and can be done without removing the DW from the cabinet.

TechnicianBrian

It isn't a real hard fix, but can be tricky if you haven't done them before. Get back to me when you get the pump assembly and I will see what I can find for you.

TechnicianBrian

I find it easier for me if I leave it in place, but I have done a ton of these. The sump assembly will be removed from the inside of the tub, so you need to remove the racks, take off the wash arm, and remove the two screws holding the delivery tube to the rear of the tub. The tube can be split in two and separated from the lower part connected to the top of the assembly. The lower part will slide to the right and unlock from the top of the assembly. The wash arm connector will have a clear Mylar ring around it so don't lose it. From under the tub, remove the drain hose and the drain pump. The pump has a keeper in the upper left corner when you look at it. Press it with your thumb and rotate the pump toward you. It will separate from the sump assembly. Now the assembly is held in place with three white tabs, one directly above the drain hose connection, one 90 degrees to the left, and one 180 degrees in the rear. Just pull them out. Next place your hand under the assembly and push up until it pops out of the tub. The thermister and motor wire harness will still be attached. Remove the motor harness and rotate the thermister counterclockwise to release it from the sump. You should be able to remove the whole thing. Put the new on back in opposite of the way the original came out. Be careful of the while cover over the motor. It must go under the tub and not be pinched in between the sump and the tub. You may need to put some pressure on it to make it seat well since it is new. Connect the motor harness and install the thermister before pressing the pump in place. Put everything back together and that should do it. I had some students do this in class today and took some pictures. Hope they help.
TechnicianBrian

Hey i want to thank both of you for your discussion on this topic and brian for the pics... I had the same problem, i laughed when i read sleach's description of the noise b/c i told my wife last week it sounded like a 747 engine in the kitchen before reading this post. The biggest issue i had with this install was ensuring that the assy was seated properly...i had to have my wife push down from the top while i re-installed the clips, also, be careful about that little plastic washer under the wash arm, it might come flying out when you move the wash tube to the side. Thanks Again, ZIP.

There are two kinds of drain pumps, one with a fixed o-ring and one with a floating o-ring and they work the same, but one is easier to install than the other. If yours hasn't leaked, you did good when you replaced it and it should be fine