That may indicate that the refrigerant is low. I believe there is a sensor on the back of the compressor that shuts it down when it gets hot. Low refrigerant will allow it to get hot. An evacuation and recharge with maybe a little more oil will tell you. They can weigh the amount that they take out. That's what was the solution to my exact same problem.... I had about 40% of what was supposed to be in it.