Noisy compressor/high temp?

Once again I am at the mercy of the experts, I have 2 issues with my Cavalier US 12-96, I have had this unit @ 1 year and have only replaced the thermostat. The first issue is when the compressor shuts off, it sounds like the whole unit is launching out form under the machine, it sounds like "sort of a knock, or like the mount is missing when it shuts down, not when it comes on. issue 2 is the temp on the top rack has been 55 degrees, not sure how long, I have just now bought a thermo. to check it, but I believe that has always been the temp since I brought the machine home last year. The thermo was set at 2 and the temp is 55 on top rack, I turned it down to 4 and the temp went to 46 degrees at the bottom rack, I did not recheck the top rack. I was afraid to set the temp any lower, because I was afraid of a freeze up of the coil. The temp coming from the botto of the machine seems very hot, Does this sound like a major problem in the future, what should I check, or do we need to wear helmets in the same room with it incase it does launch.

I sure do appreciate all input and help!

Thanks
Larry '>  '>

[globalcompressors]

Larry,

  It sounds like the compressor has broken a shock spring. Inside the "pot" the compressor block is held in place by 2 or 3 springs. If one breaks, the compressor block will kick over to one side and start rubbing or banging the inside of the can creating a noise when the torque has stopped. Usually, when the unit is running, there isn't any noise. The problem is, there is an added stress on the "high side" discharge line coming from the head assembly. Sooner or later, this line will crack or break causing hot gas to escape inside. The unit will stop cooling and the compressor will run EXTREAMLY hot to the touch. As for now, let it run. Turn the thermostat colder. You won't freeze the coil unless the box gets below freezing. As long as you have a good door seal, air flow, and the compressor is cycling via the thermostat, you should be fine. When it quits, give me a call.

Eric