The freezer seeme to only work sporadically and then not cold enough to keep icream frozen. Also whenever the compressor turns off the fridge makes a loud poping sound on and off for several minuits.

It needs a freon check... phone manufacture or your local repairman. Freon has to be added by a licensed user.

Checking the "Freon" would be the absolute last thing I would consider and I have been an HVAC technician for 35 years. It sounds like something is loose. Remove the back and look at it when it makes this noise and see where it's coming from. A popping sound could be a loose wire and this is dangerous. Here are some manuals: https://dl.dropboxusercontent.com/u/8010163/Maytag%20Refrigerators.zip
When you locate where the sound is coming from write back or send me an email. Do not keep the back off for more than a few minutes because your model will not let air go through the condenser with the back off, but before you check it out unplug it and clean the coils with spray soap and water from a hose nozzle, making sure to avoid the compressor wiring. You will need to clean the fan, too. Make sure that the blades are clean. You can put a piece of cardboard from where the fan is located to the half that the fan is blowing air into and it will work while you are looking for any loose wiring. This is temporary only and not meant to be done more than a few minutes.