2000 C280. No cooling effect. Pushbutton Module diagnostics shows compressor discharge pressure (#07) of 6.6 bar and temps around ambient on #03 (heater core) and #05 (evap temp).

I put my gauges on the system and I get a high side pressure of around 8 bar at idle rpm and at 3000 rpm.

On the low side I get about 6.8 bar at idle and when I raise the engine rpm to 3000 the low side pressure drops slowly to around 4.5 bar. Also, the low side pressure randomly bounces around a bit.

Both the suction lines and the compressor discharge piping is at ambient temp.

I suspect the compressor is the problem. Can anyone conform or suggest further tests?