My freezer is making this moaning sound when the motor is trying to cool the freezer. It does not make the sound when at rest. I am wondering if it needs some freon or something? When you unplug and restart the freezer it starts making the noise again. It doesn't stop when you open the door. THe freezer has always been stored in our garage. Model #FFU20FC4CW0

SOURCE: Freezer not working

compressor is faulty. clicking noise you hear is the overload for the compressor. not worth repair and not diy

SOURCE: Frigidaire upright not cooling

It sound like you had a freon leak, you REALLY need to get this checked by a tech. if you are leaking freon it can be dangerous.

SOURCE: Freezer Problem

If it started to cool again the compressor was running. Check the condenser and make sure it is clean. Provide as much air movement through the garage as possible . 100 degrees is a high temperature to be operating a refrigerator in.

SOURCE: Freezer Thawing Out

This will not cause a freon leak and it is possible that the door was left open, but to be certain that you don't have a defrost issue, follow the guide below to diagnose any problems. Also the warm walls are normal during compressor run times.
Below is a link that will help you with parts and diagnostic procedures that are specifically tuned to your manufacturers data plate information.
http://www.repairclinic.com/0047_3.asp
If your freezer cools but doesn't get cold enough, it may have a problem in one of several areas. To better understand the proper operation of a freezer, read about freezers in the How Things Work section of our website.

In a self-defrosting freezer, poor cooling often results from a heavy frost build-up on the evaporator coils. You can't see these coils without removing a panel inside your freezer. But if you see any frost or ice build-up on the inside walls, ceiling, or floor of your freezer, it's a sure sign of frost build-up. And that's a sign of a problem with the self-defrosting system.

Freezers should self-defrost three to four times in 24 hours. But if a component in the self-defrosting system fails, the freezer continues to try to cool, instead. Eventually, so much frost builds up on the evaporator coils that the circulating fan can't draw air over the coils. There's still some cooling because the coils are frozen. But with no air flow over the coils, the cooling is quite limited and the freezer isn't as cold as it needs to be.

An easy (though often inconvenient) test of whether the problem is with the self-defrosting system is to remove all of the perishable food from the freezer, turn the thermostat to Off, and leave the door open for 24 to 48 hours. (Keep several towels handy in case the melting frost and ice overflows the drip pan). This "manually" defrosts the freezer. When the frost and ice build-up has completely melted away, turn the thermostat back to a normal setting. If the freezer then cools properly, it indicates a problem with one of these components in the self-defrosting system:

• The defrost timer. To test this, manually advance to the defrost cycle. The unit should advance itself out of the defrost cycle in about 45 minutes.
  
  
• The defrost thermostat (or bi-metal switch). This thermostat allows current to pass through it at temperatures of 20 to 30 degrees Fahrenheit and prevents current from passing through it at 40 to 60 degrees (depending on its design). This is difficult to test, though, because it takes a prolonged, very-cold temperature to turn it on.
  
  
• The defrost heater. You can test this for continuity using an electrical meter.

SOURCE: Whining sound from motor on Frigidaire upright freezer

Hi: It sounds like you bought a frost free freezer as it has a fan. The fan will come on to circulate the air. It will not necessarly run continuosly. The noise is most likely coming from the fan. I sold Frigidaire freezers for years and they are noisy compared to a refridgerator. If you think it is louder than it was when you bought it, I would replace the circulating fan. Also look at the back wall for frost as it could be a bad defrost heater blocking it with ice. Most likely just the fan though. Since it's in a detached garage,and you won't have to put up with the noise inside your house, it could run a while before failing. The fact it's getting cold is a very good sign.Also as you asked 2'nd, a freezer is ok in an unheated garage. Don't put a refrigerator in there. Unless It is a Whirlpoll Gladiator that is designed for such applications. Use www.searspartsdirect.com to find out where the fan is if you feel it is necessary to replace it. Its not a tough job if you are handy. Their shipping is expensive so you might want to buy it locally.