My LG WM2487HRMA washing machine makes a buzzing sound off and on during the rinse cycle which it never had before. The pumps are clean and turn freely.

It sounds like some water may have gotten into the machine's pump system when you left the cap open. The noise you're hearing during the washing cycle may be due to air bubbles or debris in the pump.
Here are some steps you can take to try to fix the issue:

1. Unplug the machine: Before attempting any repairs, make sure the machine is unplugged from the power source to avoid any electrical hazards.
2. Check the pump filter: Many washing machines have a pump filter located at the front of the machine. Check your machine's manual to locate the filter and clean it out. The filter may be clogged with debris, causing the pump to work harder than usual.
3. Run a cleaning cycle: Some washing machines have a cleaning cycle that can help remove any debris or buildup in the machine. Check your machine's manual to see if it has this feature and run the cycle.
4. Call a professional: If none of the above steps work, it may be best to call a professional repair service to inspect the machine. They can diagnose the issue and recommend the best course of action to fix it.

Remember, it's always important to follow the manufacturer's instructions and safety guidelines when attempting any repairs on your washing machine.

sounds like the drain pump could be clogged up might wanna lay it on its backside and take the motor out and inspect it for any buildup inside of its self as this can/will damage the drain pump however if there is nothing there inside the drain pump then the pump needs replacing

If the drum is turning during rinse cycle and the lifting paddles are not broken you might have a pump problem if fitted with distribution pump

i have the same problem. did you find a solution?

Is it pumping out water,im guessing not! OE outlet error.The pump impellor might be jambed with a hair pin or nail.if not,the pump may just be stuffed & impellor not turning & not pumping water out.Im presuming its not pumping water out on any part of the cycles at all.Also make sure you havnt attached extra hose to the the drain hose to water your garden,these pumps are weak.hope i helped.

its probably your cold water rinse only valves solenoid thats loose on the structure or the coil itself is loose,you may not hear it all the time especially during the initial wash start fill,try this, set the washer for cold water fill only on the washer,but turn off the water valves that supply water and start your machine to a wash cycle as normal,try this and see if it dry buzzes(without water),then try the same on the hot side,then with the water still off open up the machine and you can localize the buzzing noise

An HF Code is a Water Inlet Problem- No or Insufficient Water Supply.

Press Pause/Cancel twice to cancel the cycle. Then, unplug the washer.

Run down the list again:
Make sure faucets are completely turned on.
Make sure the fill vavles (screens where water enter machine) aren't clogged.
Make sure the hoses aren't kinked, etc.

Plug the machine back in. Try another cycle. If the problem still occurs, You may need to replace your Water Fill Valve. Let me know if you need any further assistance.

sounds to me that something is stuck in your pump check the pump if you open the pump have lots of towels on hand the machine will not spin if it does not drain

Check the water pump for an obstruction in the chamber area, your pump may be sticking and that will cause the buzzing sound. The water pump runs during the fill portion of the cycle on several of the selected wash cycles to recirculate the water.

if its a direct drive remove the rotor and see if theres a loose magnet etc,hope this helps