Fridge making loud screeching sounds

Generally, in my experience, the loud screeching is caused by one of the fan motors or fan blades. There is a fan inside the cabinet (possiblle two, one on the freezer and one on the refrigerator side). Also, there is a fan underneath the unit near the compressor (probably in the back).

If the screeching is coming from underneath then pull the unit out from the wall and remove the cardboard cover at the bottom back. Now turn the unit on and check for where the screeching is coming from.

If it is the fan blade (hitting something) or the motor, you can remove these and replace them easily. UNPLUG THE REFRIGERATOR BEFORE TOUCHING ANYTHING UNDERNEATH THE BACK OF THE REFRIGERATOR.)

Good Luck!