To troubleshoot a loud refrigerator, identify where the noise comes from, inspect the components that are likely causing the noise and replace parts as necessary. If the source of the noise is the back of the refrigerator, the condenser fan, the compressor or the defrost timer may be the culprit.
The condenser fan sometimes creates noise due to the accumulation of dust or lint between the fan’s blades. After unplugging the refrigerator, clean the blades using a soft brush. Replace the motor if there is no sign of dirt build-up as the motor may be broken.
Change the defrost timer if the noise comes from the bottom of the fridge close to the front side. The entire compressor may need replacement if noise originates from the outer area of the refrigerator at the back.
Self-defrosting refrigerators have an interior fan designed to let air flow through the fridge and freezer, which is why the inside of the fridge is typically the source of loud noise. Find out if the circulation fan is causing the noise by opening the freezer and pressing the light switch. If the action produces a louder noise, then the fan motor should be replaced. If there’s a rattling noise from the bottom, check the drain pan found below the refrigerator and adjust it properly to stop the noise.