Refrigerators will make some noises, most of the noises are normal. Hard surfaces, like the floor, walls and cabinets, can make the noises seem louder than they actually are.
The noise that refrigerator makes can be divided to the normal sound and unnormal sound.
The normal sounds: The normal work sound of compressor is running, the compressor clicking sound when starting or stopping, the refrigerant flowing in the cooling system, the refrigerant eruption sound, the fan motor, the cooling system rumble, the sound of parts expanding with heat and contract with cold, these sounds are normal.
The abnormal sounds: The pipeline vibrating, a whistling sound, the compressor cylinder collision sound, the fan motor vibrating sound, the fan blade collision sound, other different sounds and so on. For above unnormal sound, or the sound affects your life and work,requires a service technician.