Dishwasher squeals right during fill?

Question

Not much to it. I can provide model and all that stuff but don't think it is pertinent. Dishwasher squeals/whistles high-pitched right when it is intaking water - super super loud. So depending on the cycle we choose this can happen 2-4 times while it is running and each time while water is coming in.

This can be repeated and happens every time. Been months and not sure the issue has gotten worse but it definitely isn't getting better. What should I check first?

Answer 1

I don't mean this as a complete answer but what I would do to start. I'm assuming you've done the obvious like checking the supply line and shutoff valve for obstructions from calcification, etc. The problem is almost certainly in the water supply system. If the external supply line is good to go then you need to go under the hood. Usually that type of sound is caused by bad bearings in a pump or other reciprocating device. It could also be caused by scale build-up in a high water pressure area which I'm sure you've considered. Anytime too much water is being forced through too tight of a bottleneck it's going to howl.

Diagnosis

I would run the dishwasher through a short cycle with the front bottom panel removed. You can sometimes determine where a sound is coming from by placing a long wooden dowel on different components and your ear against the dowel. You can also use a stethoscope but the sound might be too loud for that. If you can't identify the source you may have to slide the dw out and try the same process from the back. The process with the dowel works best when it's not in an enclosed area where sound reverberates.
Most dishwashers are fairly simple to slide out of their enclosure by removing a couple of screws. I would slide it out as far as possible onto a piece of plywood to protect the floor being careful not to kink any of the wires or hoses. The further you can get it out while still connected the better.
I would then stabilize it so it's level and relatively secure. Check all of your connections: power cord, water supply line and drain line making sure they're not compromised in any way.
Run the dishwasher through a simple fill and rinse listening carefully and observing, particularly around the fill inlet area. It is usually much easier to determine what is causing a particular sound in this way. It will help you to zero in on one or two possible problem areas. With dishwashers most of the components are under the chassis so they're difficult to access. I would once again use either an inexpensive stethoscope or a long wooden dowel to focus in on suspect areas. A wooden dowel can be butted up to a device and by placing your ear on the other end you can get a good idea if it is the one doing the howling.
You might get lucky and immediately identify the problem or you may have to do a little trial and error by replacing suspect valves, impellers, etc. Obviously start with the simple, inexpensive solutions first. You might have to end up calling in the "Maytag Repairman" but I doubt even he could give you a definitive answer without running through a similar process. Good luck

Edit

Admittedly, it is hard to get access. Some components like the water inlet are toward the front but you may need to reach some through the back. In doing this you may have to move the drain line to the sink or use an extension. Once you've identified a possible problem area disconnect power, water and drains, and turn the dw on its side which will give you better access to replace parts. There is no easy way to troubleshoot this.

Answer 2

There are Apps showing frequency spectra, e.g. spectroid. Taking screen shots of the spectrum when the (main) water valve is unchanged and when the throughput is reduced helps to find out if the problem is in the water flow or in electrical parts. A 2nd person turning the valve while watching the spectrum to check if and how the frequency changes can give a clue. Posting those screen shots here may also help.

Also the localisation is possible by moving the phone to the spot with highest level of the relevant frequency. The big electric motors of both pumps resp. inlet valves are often at the bottom, but the transparent counterflow heat exchanger which is likely to get clogged is often under the left side panel, together with more valves.

Filling the washer manually with water, closing the door and closing the wall or main water valve and starting will tell if the sound is coming from the drainage part, since the first step of the control logic should be to drain that water.

Placing the dish washer with removed side and lower panels on a table with a big hole while running helps to find the cause.

Answer 3

Troubleshoot and eliminate the most unlikely, bearing in mind that the more assumptions you have to make, the less likely it is the root cause (Occam's razor).

• the pump does not run during filling, so scratch that
• the only "active" component during filling, normally, is electrically controlled fill valve.
• a high-pitched squeal or whistle is very commonly associated with rushing water through pipes or valves where vibration is the culprit.

I would do these things while the squeal was occuring:

1st- place my hand on the water supply valve and feel for localized vibration; I would also partially open and close it and perhaps close it all the way and reopen it, listening and feeling for any change (this will not hurt the dishwasher).

2nd- I would place my hand on the water supply tubing/hose and move along it as far as possible, again feeling for vibration; I would also attempt to move the line this way and that, listening and feeling for any change.

3rd- I would pull the lower panel and find the electric fill valve. I would again feel for localized vibration; I would also manipulate the supply line at that valve, and tap on that valve, listening and feeling for any change.