Imagine this. You buy the dishwasher of your dreams, use it for a few months, and then one day during your normal cycles, the dishwasher makes high pitched noise. You are confused. What could be the problem, and how do you fix it?
It’s normal for dishwashers to make some noise when running due to valves and motors, but if yours is making a high pitched squealing noise, you have a problem you should address as soon as possible.
In most cases, high-pitched dishwasher noises come about when you have problems with the motor, pump, or inlet valve, so when you have a problem, these are the areas to pay attention to.
High pitched noise due to pump problems.
The dishwasher pump supplies pressurized water to the spray arms and pumps dirty water into the drain hose. To determine whether the noise is due to the pump, examine below your dishwasher.
Is water leaking?
The impeller seal might be allowing water inside the motor. The leak washes away the bearing grease leading to the high-pitched noise.
Impeller seals can’t be repaired, so you need to replace the motor. Thankfully it’s easy to find motors for most major brands online or from your local store.
If your dishwasher is still under warranty, contact the manufacturer and ask them to replace the motor.
Noise due to motor problems
Using a flashlight, inspect the motor and pump housing located on the bottom of the dishwasher. During the inspection, look for a slinger attached to the top of the motor.
Due to old age or improper construction, the slinger can break off and spin around the shaft, resulting in noise.
If the slinger is broken, you have to replace the motor.
High pitched noise due to debris.
Sometimes a small object such as a piece of bone, food, or broken fish fragment will stick in the dishwasher pump, making an annoying sound. To fix the problem, open the dishwasher pump located with the motor and inspect it for debris.
In most cases cleaning the pump is enough to eliminate the noise, but if there are clear signs of damage from the obstruction, you have to replace the pump.
Droning noise due to worn out bearings
The circulation pump motor has bearings that wear out over time. In most cases, the high pitched noises due to worn out bearings will come about after years of use, but it’s not unusual for them to arise early on.
When the bearings fail, they will generate a continuous drone. To get rid of the noises, replace the bearings (if your dishwasher model allows it). But if you can’t replace the bearings, you have to replace the entire circulation pump.
Noise due to water inlet valve problems
Faulty water inlet valves are the major causes of dishwasher making grinding noises. Unfortunately, it’s hard to tell whether the noise is coming from the water inlet valve without first removing it from the dishwasher.
Begin with unplugging the dishwasher, then remove the kick plate from the front of the dishwasher and locate the inlet valve.
Check that the hoses have a good connection, and there are no bends or kinks to restrict water flow. If the connections are loose, tighten them, and replace the kinked hoses.
You should then disconnect the wire connectors from the valve. Most dishwashers will have two or four wires connected to the inlet valve. To avoid confusion as you are replacing the valve, label the wires.
After setting the multimeter to its lowest ohm setting, touch each probe to a solenoid terminal. If it shows a reading of 0 ohms, the valve is fine, but if the reading doesn’t change or shows a reading of 2, you should replace the valve.
You can order the inlet valve online or buy it from your local parts store. When ordering online, take note of your dishwasher’s model number, so you don’t buy the wrong one.