***Compressor***
If the noise is coming from the compressor, the compressor might be damaged internally. The compressor internal components can wear out over time generating more noise than normal. The compressor is usually located underneath the refrigerator near the back. Pull the refrigerator out from the wall and remove the rear panel to access it. Compressors often last for years after they become noisy. However, if your compressor is noisy, be aware that it is likely to fail. The compressor must be replaced by a licensed technician.
***Evaporator Fan Motor***
When the evaporator fan motor in the freezer behind the rear panel fails, it often generates a lot of noise. This noise will be much louder when the refrigerator door is opened. If the evaporator fan is noisy, replace it.
***Fan Blade***
If the refrigerator is noisy or loud, especially when one of the doors are opened, either the evaporator or condenser fan blade may be at fault. First, check out the evaporator fan blade in the freezer behind the back panel. Try turning it by hand. If the fan blade does not turn freely, check to see if the blade is rubbing against something or if something is caught in the blade. Additionally, check the condenser fan blade in the back underside of the refrigerator to determine if it has any obstructions.