Why does my (countertop) dishwasher make a loud buzzing sound during its wash cycle

This is normal. Countertop dishwashers have two motors inside. The drain motor is a inductive type motor. They are noisy. They all work this way during draining.

If it's 12 years old, replace it.

follow the steps and fix it. God bless you

Drain Pump

If the dishwasher is loud during operation, the drain pump might be defective or might have some debris in it. This is a common problem.

Circulation Pump

If the dishwasher is loud during operation, and the noise is a continuous drone similar in speed to the circulation pump sound, it's likely that the circulation pump motor bearings have failed. Once this happens the circulation pump will have to be replaced, the bearings are not repairable.

Drain Impeller

If the dishwasher is loud during operation, the drain impeller might be broken, or there might be debris in the pump. Generally, to gain access to the pump the top of the pump housing will have to be removed.

Pump and Motor Assembly

If the dishwasher is loud the motor bearings, drain impeller or wash impeller might have worn out. All three of these components are part of the pump and motor assembly. It may be possible to replace one of the impellers, but the motor bearings cannot be repaired. In that case the pump and motor assembly will need to be replaced.

Wash Impeller

The wash impeller is a small, plastic blade. The motor spins the impeller forcing water through the spray arms to clean the dishes. If one or more blades has broken off of the impeller the dishwasher is loud. The impeller can also scrape against the pump housing if it is damaged, warped or bent.

Circulation and Drain Pump Motor

If the dishwasher is loud during operation, and the noise is a continuous drone similar in speed to the motor sound, it's likely that the circulation and drain pump motor bearings have failed. Once this happens the motor will have to be replaced, the bearings are not repairable.

Water Inlet Valve

The water inlet valve is an electrically controlled water valve. When it is new, the water inlet valve is very quiet. Over time, the diaphragm inside the valve deteriorates and deforms. This deformation interacts with the water rushing in and can cause a loud vibration, buzzing, squealing or other noises. If the dishwasher is loud during the filling cycle, replacing the water inlet valve may solve the problem.

I have the same problem as those who stated their dishes are not getting clean. If you listen to the wash cycle you should hear water sloshing around inside. If you hear just a humming sound the washer has no water. I have this problem. I had a tech come and he told me the water is syphoning out my drain and I need to change my plumbing, then he charged me $65. I have lived in this house for ten years. 6 with the washer that came with house and 4 with this Kenmore Elite. This problem started about 6 months ago. So what I have been doing is opening the door, after the humming starts and the sloshing stops, and adding about 2 L of water. It seems to wash just fine after that.

ok so If your dishwasher has worked fine in the past but, suddenly, your dishes aren't clean after the dishwasher completes all cycles:
1) Check your water heater's temperature dial to be sure it hasn't been changed recently.
2) Be sure dishes haven't prevented the detergent dispenser from opening properly during the wash cycles or kept the spray arms from turning, the lower arm from rising, or the spray from reaching the upper rack's dishes.
3) During the wash cycle, listen to the spray arm spinning inside. If it seems to be spinning poorly, clean out the spray holes in the spray arm(s) with a stiff piece of wire; wait for the machine to cool, and then remove the spray arm(s) by unscrewing the hub cap and lifting the arm(s) off Regards Gizokieth

have you ever seen green led "Clean" light flashing? before or about the same time the buzzing sound started? and if so that would indicate that the control senses a fault in the temperature rise during the heating cycle and that the electronic control could be reset by initiating a service diagnostic cycle.(which is what you were trying to do) pls reread your manual there are times during that sequence that some buttons have to be pushed at the same time and within a certain amount of time..possible that your machine also has a bad timer which would give you a buzzing noise..if thats the case I would recommend replacing the cpu or control board..or the machin all together..The Kenmore Ultra Wash Quiet Guard name is sears but whirpool has the contract to produce all "kenmore products.hope that helps.

if you have a torx 20, and torx 15 screw driver, you an remove the screws from the top plate of the wash motor, and underthere youll see another t15 screw converingthe "chopper" assy, sounds as if a seed, of chicken bone, perhaps apiece of glass hasgottne down there

An aging water-inlet valve can sometimes fail slowly, rather than all at once. It can shudder on and off rapidly, causing the incoming water lines to shake, rumble, and rattle--sometimes violently. If yours is doing this, replace the inlet valve.or may be its due to
Heater fanIf the heater fan bearings are rusted or worn, they may squeal, or scrape loudly during the drying cycle. If this is the problem, replace the fan motor. Alternatively, the fan blade may be loose. If so, you need to replace it.

How deep do you want to get into this?It sounds like the wash pump motor bearings that are worn.You can pull the unit out flip it over and wd40 the bearings in the motor or you can replace the bearings.Try to lube them first.

It could be the impeller on the motor. The impeller fits over the shaft of the motor and might have split/broken up. That funny noise is probably the shaft spinning inside the damage impeller. Fortunately the impeler is fairly inexpensive and easy to replace. I believe there are one or two parts/covers to remove that are held in by a roughly half dozen torx screws.