This problem is a mind blowing one. The car blows fairly cold air at idle. But when driving, it gets significantly warmer. The air never really cools off the cabin. Sometimes when Turing the car at a decent speed, the air will cool slightly, then go back to being warm.

AC compressor is working, no refrigerant leak.

2006 SS

 

Have you had your system vacuum tested to make sure it is full correctly?

Could be a blend door issue, could be air in the system.

 

How are the pressures?

I had a somewhat similar issue on my 08 impala. The system had to be opened to service a component (a tube got externally damaged and had to be replaced). It was overfilled a bit after reassembly and was just squeaking by functionally at idle, but would shut off the compressor when you got some heat / rpm in it (ie from driving) due to over pressure.

 

Have u check cabin filter if it has one!