Hello fellow Mini enthusiasts,

I have a 2008 R55 with the IHKA HVAC control system. The problem I am having is that the AC system is not cooling. Heating and diverter doors appear to be working correctly. When the AC is on the the air temperature coming out of the vents is the ambient air temperature. The AC system static pressure on the low pressure side is 45 psi, the high pressure side reads 45 psi. When the AC system is turned on the compressor clutch engages the compressor starts working. While the AC compressor is running the refrigerant circulating through the system makes a loud hissing sound like air being blown out of an air nozzle. The AC system pressure while the system is on, low side is 113 psi and the high system pressure is 116 psi. I did a two minute timed run of the AC to see if the compressor cycles on and off and the compressor stayed on for the entire test and never cycled off and on. According to AC pressure chart I was using for research (https://www.jamcoautoparts.com/syste...shootingchart/) it suggests the following:
Pressures at or Near Equal
• A/C compressor failing internally
• A/C compressor variable displacement function inoperable
• Expansion valve failure

Has anyone had a similar problem and if so what components did you replace to fix the problem?

Static Pressure

Running Pressure

Any help would be appreciated.

Thanks!

 

Never fixed a mini ac but it does sound like you have a blockage in the expansion valve.

 

ChiefM thanks for the suggestion about the blocked expansion valve. It is the least expensive part so that's where I will start.