Hey there fellow Mini owners, I recently was topping up the refrigerant on my moms 2006 R50. System still had refrigerant in it so didn't put a vacuum on it before topping it up.
Purged my gauges, filled it so the low side is in the 35-40 range, left the car running for 5 minutes and came back to the high pressure side in the 290 PSI range! Did a bit of research and found out about the radiator fan low speed resistor problem so bypassed the resistor and got the low speed working again. Verified AC pressures again and they were low once again (low side around 25 psi and high side at 120 psi so the low speed fan helped high side pressure go down) so after topping it up again i got the low to 40 psi and the high side to 250 psi (29C day).
<----- (before rad fan fix, 25 psi low, 290 psi high)


(After replacing rad fan resistor 25 psi low and 120 high)



(After rad fan resistor and more refrigerant 40 psi low and 250 high)




After checking the temps in the car the vents are warm on the driver side but ice cold on the passenger side so I immediately thought of a blend door issue like on my automatic ac controls in my Volvo, but 5 minutes later I realized this car has manual ac controls (manual fan control, manual temp control, manual placement control) so I knew there was no blend door.

So I pulled the glovebox off, saw the glovebox cooling tube and decided to stick a thermometer in there to measure evap temperatures... The evap is 3C on the passenger side and if you stick the thermometer a bit further to measure the driver side evap temp... ITS 47C!!!!!!!


Evap temp passenger side




Evap temp driver side





Do you guys have an idea what it could be? Is it possible the heater core is somehow bleeding heat through the flap to the evaporator? I'm thinking it's the expansion valve...
I might stick a camera through the glove box cooling hole but I doubt I'll see anything alarming... Car is holding pressure so it's not a leak!



thanks for the help in advance!

 

On my R56, I had an experience where the temp control **** skipped a tooth, and the blend air door wasn't closing off the heater core all the way. Your AC system (besides the leak) is functioning properly. You've probably have a faulty door inside the plenum. Oh by the way. you do have a blend air door; that door blends airflow from the compartment in the plenum with the heater core with air flowing through the compartment with the evaporator core. The problem with the R50-R56 minis is you have to pull the dash to get the plenum out.

What I think you meant to say is you don't have dual-zone climate controls where the driver and passenger can select different temperatures.

 

This usually means that you have low refrigerant, but if you are seeing 47C, meaning it is hotter than ambient (hopefully!) you might have either a damaged blend door or you have a restriction in the evaporator that is greater than the restriction in the expansion valve, so the systems pressure reducing orifice is technically inside the evaporator.

Two things you can do to check that won't require removing the dashboard:

Get some needle nose vise grips and pinch off one of the heater hoses. This will prevent the heater core from getting hot coolant. See if the hot vent output gets cold. (If this is the problem then it may take a minute or three to remove all the heat from the heater core to get a noticeable change)

To check for the possible plugged evaporator, hmm. You'd need to be able to put your hand on the low side line on the evaporator side of the expansion valve and I'm not sure that would be possible. It should be ice cold.