Damep

Hello guys. My Rs ac has been going in and out. I got it vacuumed and refilled with the correct amount of freon. They found no leaks in the system. It ran pretty good for a week or so but once the car sits out in the warm the ac just blows warm air and doesn't get cold at all. Once the vehicle cools down either from the garage or keeping the ac off while driving for extended periods of time I turn it on and it will start blowing cold. When it blows warm I smell a light dank smell and hear a slight whistle sound as if something is turning on and off. Please any help??? Thanks