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FIXED KitchenAid Dishwasher KDTM404ESS2 making an intermittent thumping noise.

BMac85

Premium Member
Joined
Dec 8, 2021
Messages
9
Location
Wisconsin
Model Number
KDTM404ESS2
Brand
KitchenAid
Age
1-5 years
Hello everyone,

About a year ago, my 3 year old Kitchenaid dishwasher stopped circulating water. I ended up replacing the entire sump and motor assembly and all worked again. However, over the months I’ve randomly heard a thumping noise during certain parts of the wash cycle. I always figured an arm was hitting something (we have tall plates), but lately it was bugging me, so I decided to investigate. Sure enough, after removing the lower plate, it sounds like it’s coming from underneath the dishwasher itself.. perhaps from the diverter motor? The noise only comes up periodically during the wash cycle, and everything seems to be working/cleaning fine.

Anyway, I’m not 100% certain if I ever had this noise before I switched out the sump and motor assembly a year ago, and I’m a little frustrated as to why I’m having problems again; although the first time I suspected it was a filter problem as I know it’s common with this model.

Below is a video of the sound. Any ideas? Thanks!
 

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Jake

Appliance Tech - Admin
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Messages
129,011
Location
Redmond, Oregon
Hi,

I've not heard that noise before on any dishwashers, I don't know where its coming from.

Hopefully another tech that knows can post in your thread here and shed some light on this issue.

Jake
 

BMac85

Premium Member
Joined
Dec 8, 2021
Messages
9
Location
Wisconsin
Thanks for the reply, Jake!

I got home from work this morning, and reinstalled the bottom sprayer (I didn’t know that certain part had to be pointed toward the lower right corner before you lock it in), and also I noticed the heating element was out of the front clip and just resting on top of it. I put it on quick wash, which is 56 min long - and the noise didn’t come on until the 19 min mark; which usually it comes on well before that. So, I opened up the door, and it looked like the spray arm was touching the bottom of the basket. I sort of pushed back down on the spray arm and “re-leveled” it, and the noise went away and did not return.

Is it possible the noise is coming from the lower sprayer hitting that basket? If so, how do I keep it from doing that again? I’m pretty confident I have it installed correctly now and locked in. I inspected the gears and the holes on the spray arm, and everything looked ok to me.

Thanks again!
 

BMac85

Premium Member
Joined
Dec 8, 2021
Messages
9
Location
Wisconsin
Also - just now I noticed the entire dishwasher seemed to be leaning slightly forward in the cabinet, so I just raised the 2 front foot pads and now it’s much more level. I will see if that makes a difference as well. I’m hopeful, because it seems the spray arm was catching the bottom of the basket in the rear. Still, not sure why a “knocking” or “thumping” noise would come from that. Hopefully the diverter motor is ok.

Please let me know anyone’s thoughts!

Thanks!
 

Jake

Appliance Tech - Admin
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Messages
129,011
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and also I noticed the heating element was out of the front clip and just resting on top of it.
Did you fix that yet?

So, I opened up the door, and it looked like the spray arm was touching the bottom of the basket. I sort of pushed back down on the spray arm and “re-leveled” it, and the noise went away and did not return.

Is it possible the noise is coming from the lower sprayer hitting that basket? If so, how do I keep it from doing that again?
Possibly, that heating element being out of the front clip could be the cause of that too.

Jake
 

BMac85

Premium Member
Joined
Dec 8, 2021
Messages
9
Location
Wisconsin
Yep, clipped the heating element back in before the quick wash test this morning. I also noticed the heating element was warped a little, and clipping it back in definitely helped it stay lower. Then the noise did not come on until 19 min left in the cycle; which is better as it usually shows up earlier. When it did happen at the 19 min mark, I quickly opened the door and noticed one of the sprayers on the spray arm in the rear of the dishwasher was touching the bottom of the bottom rack - leaving me to notice that the entire dishwasher actually was leaning forward in the cabinet.

So, I leveled entire unit so it isn’t leaning forward anymore, so I’m hoping maybe that helps, too.
 

Jake

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Hopefully that took care of that noise.(y)

Thanks for the update!

Jake
 

BMac85

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Joined
Dec 8, 2021
Messages
9
Location
Wisconsin
Just to update again - after leveling the entire unit, the noise came back a couple cycles later. Still an improvement. But then I noticed a white gunk was coating several areas of the dishwasher. Kind of hard to describe but it did not easily break down. I ran some Affresh tablets through the dishwasher, and that took care of the noise for another 6-7 cycles. However, the noise came back again yesterday, although not quite as badly. So thoroughly cleaned everything, took off the lower spray arm, flipped it over to find 80% of the holes on the bottom of it were completely clogged by the white gunk. I cleaned it all out thoroughly and the noise is gone again. Hopefully that takes care of it. I’m assuming that thumping noise is the pump being backed up?

Anyway, back to the warped heating element. It is raised in one area and lower in another. I believe this is from the element never being clipped into the front clip. I believe it came from the store and was installed like this. And I’m sure we’ve been using it with it being warped for awhile and just never noticed. Now it’s secured into that front clip, but still a little higher in one area and lower in another.

I’m pretty sure the element isn’t hitting the lower spray arm, or resting directly on the stainless steel interior of the dishwasher, so is this element still safe to use? Everything seems to be heating and drying fine, just not sure if it being a little warped is a big deal or not?

Thanks again for all the info!
 

BMac85

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Dec 8, 2021
Messages
9
Location
Wisconsin
Here’s a pic for reference. Never mind the white stuff in the pic, that’s just a little milk from the
kids’ breakfasts.

0B5510F8-B469-4235-B633-25631A751E8D.jpeg
 

Jake

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Ok, yes I see it. Its best to order and replace the heating element at this point, its not safe to run it that warped and discolored.

Here's the heating element for your model:
Heating Element Assembly W10703867


Let us know how it goes.

Jake
 

BMac85

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Dec 8, 2021
Messages
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Location
Wisconsin
Thanks for the reply. It’s actually not all that discolored, I believe the picture is misleading there. It has a little film on it most likely from the dishwasher cleaner I put through there last night - and it wiped right off this morning after the picture.
So, besides that, may I ask why a little warped wouldn’t be safe? Again, it isn’t touching anything, just bent in that one spot.

Thanks again!
 

Jake

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may I ask why a little warped wouldn’t be safe?
Bent in one spot means its weak in that spot and its just a matter of time till it breaks. And pray to God it kicks your home breaker OFF when it breaks or someone touching the water can get electrocuted.

Jake
 

BMac85

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Ok, point taken. I have one ordered and will be switching it out. 👍

But… I think I finally solved the mystery of the noise. What it is, is the lower spray arm is actually hitting and sometimes getting caught up on the side of the dishwasher. Of the three “branches” of this particular spray arm, the branch with the largest sprayers (the geared one) is the one hitting the side of the dishwasher interior. We caught it in the act.

I thought I was installing it correctly with the largest (geared) branch pointing towards the lower right corner and clicking it in to lock it? The spray arm doesn’t look broken or damaged at all, everything moves and turns as it should, but I had no idea it was that finicky apparently.

Does anyone have any idea how to install it perfectly to hopefully get it to not hit the side of the dishwasher as it spins?
 

Jake

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lmcancu

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Dec 30, 2021
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h7e5m7
Not sure if you managed to put on the lower wash arm correctly yet. I have figured it out, and its a little tricky. There is a tab on the arm itself that slides into the bottom connector of the dishwasher. Place the lower was arm on the unit, with larger 3 starred arm facing the right of the unit. Then turn the gear until it aligns with tub connector (see pictures), the whole arm should drop slightly once you have found the correct position. You should then turn the gear 1/4 turn clockwise until you hear a click (the tab has slid into the tub connector). You shouldn't need too much force. I wore a glove to do it.
 

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BMac85

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Location
Wisconsin
Thanks for the reply. Yeah I figured it out.. once I bought a new lower spray arm and the diverter cover to which it connects. Everything sounds and works fine now. Found a handful of YouTube videos where many others have had the problem of worn out gears on this particular spray arm. Turns out I was installing it correctly, but the gear itself was super loose. New one is nice and snug. Here’s to hoping this one lasts longer than 3.5 years.
 

Jake

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