Diagnosis
The condenser fan motor is hitting its housing or has debris on the blades. This fan cools the compressor and cycles on under high load.
How to Fix It
Access and inspect the fan. Unplug the unit. Remove the toe grille and the rear access panel at the bottom. Locate the black fan near the compressor. Spin the blades by hand. Check for obstruction. Ensure the fan is seated properly on its motor shaft.
If That Didn't Work
The fan motor bearings are likely worn. Replace the fan motor assembly (Part # WR60X30328). This is a direct plug-and-play component. No refrigerant lines need to be touched.
Heads Up
The noise often correlates with the defrost cycle or during hot ambient temperatures. Let the unit cool down and unplug it for at least 1 minute before performing any inspection for safety.