Running refrigerators tend to make noises, and many of these sounds are quite normal. When your fridge starts to make a noise that is out of the ordinary, however, it can indicate a variety of issues. Doing something as simple as leveling your fridge or replacing a part may solve the issue.
Determine where the noise is coming from. Noises coming from different parts of the fridge point to specific issues. Determining if the noise is coming from the inside, outside or bottom of the refrigerator helps you to diagnose the problem.
Check that your refrigerator is level. If it is not, place a small piece of cardboard or wood under one side to make it level. Leveling a fridge can automatically eliminate troubling sounds.
Open the freezer to see if the noise gets louder. If the noise becomes louder with the freezer open, the noise is likely caused by the evaporator fan. If the evaporator fan is the culprit, replace it to get rid of the noise.
Pull the refrigerator away from the wall, and check the condenser fan at the back of the fridge. A metal panel may cover the fan, which can be unscrewed. Listen to see if the fan is the source of the noise. If it is, the fan may need to be cleaned or replaced.
Listen to the bottom of the refrigerator to see if the sound is coming from underneath. If you hear a rattling sound, the fridge's drain pan may be ajar. Jiggle the pan to snap it in place, or secure it to the fridge with tape to stop the rattling.
Unplug the refrigerator, and listen to the back side of the fridge. The fans will immediately stop running. If the back of the fridge continues to make a noise after the fans have shut off, the sound is most likely coming from the compressor, which is located at the back of the fridge, near the bottom. If you have a compressor problem, you either have to replace the compressor or the entire refrigerator.