Is Your Dishwasher Making a Grinding Noise During the Wash Cycle?

Dishwashers tend to be the loudest appliances in most people’s homes — some even make noise when they’re off! Still, you shouldn’t ignore sounds that may point to the existence of a bigger issue inside the appliance. So what does it mean if your dishwasher is making a grinding noise during its wash cycles?

Well, you might be relieved to hear that this matter isn’t necessarily something you need to lose sleep over. So let’s start by explaining when ignoring that type of sound would be acceptable — and what you can do to muffle it if you feel like you have to.

Repairing a dishwasher that is making grinding noise.

Grinding Sounds Are Typical in Dishwashers With Electric Controls

Dishwashers are appliances that contain a system of valves, rotating spray arms, fans, and other mobile parts. There’s no way to prevent them from making some kind of sound. Unless you keep your machine in a soundproof chamber, that noise is bound to reach your ears. So you might have to make your peace with that grinding.

If your dishwasher has been making a grinding noise since the first time you used it, the sound is probably normal. That’s usually something we see in machines with electric control panels. You see, these panels are typically supported by a motor-driven electrical switch device. Therefore, like any other motorized component, it can produce a low-level grinding noise as the gears spin.

Electric control panels can also emit clicking noises, but you don’t have to worry about that either. Both grinding and clicking sounds are fairly normal in these kinds of machines. If you can’t stand that kind of racket, you could replace your dishwasher with a quieter model. Alternatively, if you’re not ready to throw in the towel on your trusty old machine, there are ways to muffle the grinding sound.

What to Do When the Grinding Noise Is Par for the Course

If the normal operating sounds of your dishwasher are too distracting, you could schedule the wash cycle for when you’re asleep or out of the house. Alternatively — or additionally, if you’re still looking to reduce the noise, you could insulate the appliance.

Most dishwashers come with some kind of insulation or padding. However, it’s usually much too thin and flimsy to be effective. So if you really want to muffle the grinding noise, you’ll have to buy regular blanket insulation. Look for dense, synthetic or ceramic batts that are at least half an inch thick.

After you get your hands on the insulation, you’ll have to install it. Start by disconnecting your dishwasher from the electric and water supply. Once you do that, you may also have to unscrew the appliance from the counter or the surrounding kitchen cabinets and wiggle it out. At that point, you’ll be able to remove any existing insulation and replace it with your new one.

Lastly, you’ll want to secure the insulation by taping it down before pushing the appliance back into place. Having a thicker layer of insulation around your machine will:

  • Protect the counter and the wooden cabinets from condensation and heat
  • Prevent vibrations from passing to the surrounding kitchen elements (if that’s a big concern, consider using anti-vibration pads as well)
  • Muffle the sound of running water and grinding gears coming from inside the dishwasher

If the appliance in question is particularly noisy, you could cover the front side with another layer of padding. As I have explained in my article about dishwasher insulation, you could make that panel out of a soundproof blanket or curtains. You could also bolster it by inserting a piece of MLV between two layers of fabric and sewing them shut.

Repairing a dishwasher that is making grinding noise.

Reasons Your Dishwasher Is Making a Grinding Noise

Of course, the instructions I just gave don’t apply to all dishwashers. If your appliance doesn’t have an electric control panel, the grinding sound may have a different source. In fact, if the machine started sounding off suddenly, there are several potential explanations you ought to consider. Moreover, each of them would require a different troubleshooting approach.

Misplaced Items

Displaced or improperly loaded items are one of the most common causes of the various noises a dishwasher might make during a wash cycle. Luckily, confirming that you’re dealing with that problem should be easy enough. You’ll just have to tweak a few plates — or run a wash cycle on an empty dishwasher.

If your dishwasher ever starts making grinding sounds in the middle of a wash cycle, wait until the mid-cycle then open the door. Doing this shouldn’t be dangerous as long as you take a step back to allow steam to escape before checking the bottom of the machine. When the air clears, pull out the lower rack and check for utensils and other small items that might have gotten dislodged.

Chances are, the spinning arm at the bottom of the machine is just rubbing against an object that’s stuck under it. With that in mind, you’ll also want to check the top spinning arm. If some of your pot lids and plates are sticking out, the arm could be hitting them, which might explain the noise you’re hearing. To fix that, rearrange the contents of the machine until the arm can spin without hitting anything.

If you don’t spot the culprit right away, you could give the rotating arms a spin manually. However, there’s a chance that the bits that are making the noise aren’t visible at all. Particularly small parts like pieces of glass or random screws could have made it past the drain impeller.

Small Items in the Drain Impeller

The drain impeller is the system underneath the spinning spray arm at the bottom of the machine. To properly diagnose a noise that might be coming from that direction, you’ll have to fully empty the machine and remove the lid from the drain.

If you stopped your machine mid-cycle, let it run its course before getting to the bottom of this issue. Even though listening to that grinding sound can be downright excruciating, whatever is causing it probably won’t damage the inside of the drain impeller. When you’re ready to investigate, you’ll first want to remove the racks, spinning arms, and drain the impeller lid.

Everything should be fairly straightforward, but you can use the video below to figure out how to take out all those components. Better still, you could find videos of people disassembling the dishwasher model you own. In any case, the video I’ve linked to will show you how to check for loose parts around the drain impeller.

If anything made it to the chopper blade section, that’s probably what’s causing that buzzing and grinding sound. But don’t worry, it’ll go away after you clean the area out. Ideally, you would go through this process yearly to keep the blades free of obstructions.

Lack of Lubrication

If there are no loose items on the bottom of the machine, the grinding sound could be the result of insufficient lubrication. That’s something that could happen to new machines as well as old ones that just haven’t been used in a while.

If you have a brand new machine and the grinding sound goes away after a few wash cycles, it probably just needed a few runs to distribute the water throughout the system. Appliances with this issue exhibit the same difficulties any time you let them fully dry out. So an older machine you haven’t used in several weeks or months may produce some grinding sounds too.

There’s no reason to believe that this issue won’t resolve itself. However, you could help things along by pouring two quarts of water into the machine before running a wash cycle.

If the grinding sound is accompanied by consistently low water pressure, you might have to check your water supply pipes, too. Specifically, you should find out if the water inlet valve underneath your dishwasher is functioning properly.

If you find a puddle under the machine, that may be where you’re losing pressure. In that case, you would hear other sounds, including hissing, squeaking, and dripping, along with the grinding of dry machinery.

Broken Fan

A malfunctioning fan assembly inside the dishwasher door is yet another potential cause of the grinding noise you’ve been hearing. Unfortunately, if that’s not functioning properly, you’ll just have to bite the bullet and replace the whole thing.

In addition to being quite noisy, broken fans can make dishwashers stop working in the middle of a wash cycle. When that happens, the only solution is to wash your dishes by hand while you wait for your new assembly to come in.

Once you have everything you need, you’ll want to cut the power to the dishwasher before doing anything else. Then, you can take off the outer panel of the machine door as shown in the video. If your machine doesn’t look like the one in the tutorial, consult the user manual of your dishwasher. From that point on, replacing the old vent and fan assembly and putting everything back the way it was should be a breeze.

Malfunctioning Drain Pump Motor

If the noise your dishwasher is producing is something like the one you hear in this video, blame the drain pump motor. High-pitched grinding or droning is a sure indicator that the motor has reached its limits. You’ll probably have to get a new part that fits the machine you have.

The installation process shouldn’t be too taxing. You’ll have to disconnect the power and water supply, as always, and take the appliance out from underneath your counter. I explained how to do that in my article about dishwasher insulation. Once you have extricated the machine, lay it on its back to disconnect the drain pump motor from the bottom.

Unscrewing the part and returning the dishwasher to its place should take no longer than ten minutes. But remember to do your research before you take a wrench to your dishwasher. The pump can look different depending on the make and model of your machine. So make sure you’re removing the right part!

Don’t Let Your Dishwasher Become a Nuisance

Even if your dishwasher naturally makes a low-level grinding sound, there’s no need to just put up with it. You could use blanket insulation to muffle the noise and finish the job with a thick front flap. Alternatively, you could simply do your best to soundproof the kitchen, paying special attention to the door.

But what if your dishwasher wasn’t always as noisy as it is now? Well, in that case, I’d start by making sure the drain pump motor and fan assembly are fully functional. You can always fish for loose items inside the machine — but replacement parts can be difficult to track down. Still, if you decide to throw in the towel, you could always get a better, quieter model instead!


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