If your refrigerator is making a loud noise, try these troubleshooting techniques. Video

One of the possible causes of a loud noise is an obstructed freezer fan. If there is a buildup of ice behind the back panel, the fan will begin scraping against the ice, causing the sound. This is often caused by overstuffed freezers, as the air is not able to circulate freely.

Remove all items, trays, racks etc. from the freezer. Remove the back panel to access the fan/coils/etc. Leave the freezer door open to assist with the ice melting - you may want to keep towels or a Shopvac on hand for the mess!

Next you'll need to defrost the ice buildup. This can be done with a hair dryer, steamer, warm water, or a similar method. As the ice melts, it will syphon out through the drain hose at the bottom of the refrigerator. The water collection tray that may overflow, so be prepared.

Alternately, the refrigerator can be left unplugged overnight to allow the ice to melt. You can find more troubleshooting in this related article.