Dishwasher makes grinding noise during wash cycle (after pre-wash). noise persists for 15-20 minutes. It seems as though the inlet valve doesn't open during this phase of the cycle. adding water to the dishwasher manually eliminates the noise and water circulates through the wash arms. I'm trying to determine if this is a controller issue or a valve/pump issue.

Sears Parts Direct is one source of the parts diagrams, https://www.searspartsdirect.com/model/1vc37q1bdj-003204/lg-wm3987hw-washer-parts . See the Dispenser assembly parts diagram for the water inlet valve. If you can watch the entire cycle, try turning off the shut-off valves for the washer inlet hoses after the rinse cycle and before the dry cycle starts. Water should not flow into the washer/dryer with the shut-offs closed.

I've seen inlet valve solenoids fail in the open position or in the closed position. I've never seen a control board that sent open messages randomly. (Sometimes, there is damage to the control board or corrosion or damaged wiring that stops the control board from sending the open/closed message to the solenoid.)

I hope this helps.

Cindy Wells

How To Fix A Washing Machine Making Noise During The ...

removeandreplace.com/.../washing-machine-making-noise-during-the-sp...

Jul 27, 2015 - Agitator directional cogs aka "agitator dogs" (top load washers) ... If you hear a rubbing sound or the drum spins uneven, then the ... A washer making a loud noise during spin cycle can also be caused ... The clutch in a washing machine connects the inner wash tub to the ..... May 8, 2015; High Water Bill?

Dishwasher Making Loud Grinding Noise During Wash Cycle

removeandreplace.com/.../dishwasher-making-loud-grinding-noise-durin...

Apr 11, 2014 - Dishwasher Making Loud Grinding Noise During Wash Cycle ... GE, Whirlpool, Frigidaire, KitchenAid, Maytag, Kenmore, and LG) this is a .... Our Amana dishwasher is making a loud, high-pitched squealing noise throughout the wash ....Out Of A Washing Machine - Top Load & Front Load September 30, ...

All comments on Loud dishwasher Frigidaire Gallery mode ...

https://www.youtube.com/all_comments?v=v-arYb20kOk

see this causes:
Water-inlet valve
test the inlet valve for defective and replace
Motor
bearing worn replace
Heater fan
bearing worn, replalce
Pump open the pump and take out the sediment, or debris inside, or replace.

You might want to check the wash pump inlet for junk

HI. here are the most common issues that will cause a noise during the wash.

* Check the spray arm for damage and obstructions
* Check the inlet filter screens
* Test the water inlet valve(see below for test procedure)
* Check the motor and mounts- The motor may e loose or one of the mounts may have separated form the housing. this will cause mis-alignment.
* Check the fan motor and blade
* Check the drain for obstructions


NOTE

If all checks out above, the culprit will be a cracked pump impeller. this will occur if the drive stud becomes unstable, allowing the impeller to partially separate form the motor spin drive stud. this will cause the impeller to rub or grind during the wash cycle. If this is the case, there are impeller repair kits available for purchase that will correct this issue.

This isn't a solution but rather a comment, if the problem is happening only during the fill, then it could be the water inlet valve. Perhaps there is a soliniod going in the valve, watch to see if the fill cycle starts to dimminish over time. Does the sound come anytime the washer fills, ie: rinse cycle? if so I would replace the valve, probably 50 dollars would get you a new one and you can do it yourself to save a little more cash. good luck.

if you have a torx 20, and torx 15 screw driver, you an remove the screws from the top plate of the wash motor, and underthere youll see another t15 screw converingthe "chopper" assy, sounds as if a seed, of chicken bone, perhaps apiece of glass hasgottne down there

Well done by resolving this problem. The other way to avoid the siphoning problem through the drain hose is adding an air gap valve/connector (available at any hardware store). You can use it even if you don't have a garbage disposal in your kitchen sink. That will assure that you have the proper height of the drain hose.
Hope this helps!

It could be the impeller on the motor. The impeller fits over the shaft of the motor and might have split/broken up. That funny noise is probably the shaft spinning inside the damage impeller. Fortunately the impeler is fairly inexpensive and easy to replace. I believe there are one or two parts/covers to remove that are held in by a roughly half dozen torx screws.

You might have something bouncing around in the wash pump inlet in front of the "chopper". Remove the lower arm and upper arm supply tube. Remove the screws then remove the screen, accumulator and inlet protector. You should see debris in front of the screen.