Is it the motor or the pump?

Dishwasher Repair
1

The dishwasher makes a loud grinding noise when it is in operation. How do I determine which is the defective part? Any help would be greatly appreciated.

Thanks,
Tom

2

Tom,

Remove the lower spray arm, the spray arm support and filters from inside the dishwasher. Check for any broken glass or other foreign objects.

Here are the breakdown diagrams and Replacement parts for FRIGIDAIRE FDB2810LDC1 Frigidaire/dishwasher | AppliancePartsPros.com

Gene.

3

Gene,

I removed the spray arm and screen but did not find any debris. I even risked slashing my finger by poking inside the pump inlet. Nothing :mad:

The grind/whining noise is not constant. It ramps up and down as it advances through the cleaning cycle. It is quiet as water enters the tub, but you can hear it roar as it starts to cycle the water.

Next steps?

Thanks in advance.
Tom

4

You may want to check the fill level. Could be the motor is cavitating (sucking in air). You would also see poor wash results, if it is not filling correctly.

Most units fill to just under the heating element but some do fill to just over it. I am not sure which is correct for this unit.

You can check it by adding a couple quarts of hot water just after a fill, if the racket stops then that is probably your problem. Just be careful that you do not overfill it.

Low fill is usually caused by a partially clogged filter screen on the input side of the valve.
Remove the valve from the machine and check/clean the screen.
Do not permanently remove it from the valve as it is there to prevent crud getting in the valve, holding it open and causing a flood.

5

Denman, thanks for the suggestion. I will try that tonight and report back the results.

Tom

6

No dice. There was plenty of water in the tub, it covered the screen completely. Any other suggestions?

Thanks to all who are helping me out!
Tom

7

I too am following this forum because I am having the same problem. So far none of the solutions above have solved the problem. Please continue to offer advice in this forum. Mine is a Frigidaire Model FEF355EBA. Thanks.

8

Dan,

The model number you posted is for the range, so what is the questionable appliance and what exactly is wrong with it?

If this is the range, you opened the thread in the wrong forum. You have to go to the “Oven repair” forum.

Gene.

9

I’m sorry. The dishwasher model # is FDB126RBB4. It too is making a loud grinding noise during the washing. Like I said, I tried all the previous suggestions with no success. Thanks.

10

Dan,

If there are no foreign objects inside the pump, then most likely the problem is a bad wash motor.

Here are the breakdown diagrams and Replacement parts for FRIGIDAIRE FDB126RBB4 Frigidaire/dishwasher | AppliancePartsPros.com

Gene.

11

Tom,

The same advice should work for you as well.

  • For your dishwasher the wash motor AP5272381

Gene.

12

Is this something that I could replace (I’ve never fixed a dishwasher), or would I need to hire a pro?

13

Dan,

If you know how to handle a simple tools you probably can do it. The instructions are attached to the reply. You can save more than $150, doing this repair yourself.

Gene.
Pump and motor assembly.pdf (225.3 KB)

14

Gene,

Thanks for your help. I’ll be ordering the motor and will be replacing this DYI. I probably won’t get around to it until next week, but I will post the results here.

15

Swapped out the motor this morning and the grinding noise is completely gone. The old motor probably had a bearing that went, you could hear a grinding noise when turning the motor by hand.

Some tips I can offer someone else.
[LIST=1]

  • After disconnecting the water in and waste out hoses, slide the dishwasher out. It is a lot easier to turn the retaining clips that are located UNDER the dishwasher.
  • There is a hose that delivers water to the top spray arms at the rear of the dishwasher that needs to be removed. I also removed something that looked like a sensor that was attached to the motor/pump assembly that was attached with 2 torx screws. This allowed me to completely remove the assembly to replace the motor.
  • There were 5 torx screws, 3 inside the assembly and 2 on the outside metal bracket. I used food grade silicone lube (home brewer here) instead of the Vaseline on the two gaskets. Petroleum based Vaseline may degrade the gaskets over time.
  • The large gasket around the pump/motor assembly was the most difficult part. I was wrestling with the gasket for a good 15 minutes before I had a great idea to lube the tub and motor assebly with my silicone lube. The gasket was then placed on the assembly and set into the tub. The lube helped the gasket stay on the assembly as well as slide the assembly/gasket into the seat of the tub. Only took one try after applying the lube.
    [/LIST]

It took me about 1.5 hrs to complete this job. If I had to do this again it would only take me half that time. It takes some flexibility to get to some other parts under the washer. Also, it is very awkward trying to get leverage inside the tub with the door open.

Thanks again to Gene!