BMW Repair: Fresh Air Vents Blows Warm Air, two inlets, heater hoses

Question
I have a 2003 330ci (last 7 from VIN JU98120) that blows warm to slightly hot air through the vents even when the weather is cool and the vent settings are on "fresh".  I suspect that either the blend door is not fully closing or there is a problem with the shutoff valve for the heater core (if such a valve exists on newer cars).  

Here's what I've done so far (all on a day when the outside temp was in the 60s:
1. set the vent to outside (fresh) air and the setting on the lowest temp
2. set the vent to recirculated air and the setting on the lowest temp
3. turned on the AC (fresh setting)

I seem to get the same results from steps 1 and 2 but the air does get into the cold range, albeit slowly, with the AC on (as expected) and does not seem to be warmed in the same manner as the vented air.


Any steps to help diagnose this issue?  Is there a way to isolate this problem?

Thanks,

Steve


Answer
Steve, Evacuate and recharge A/C system. Be sure to use some ultra-violet dye oil in the recharge to help in leak detection in the future. Don't use refrigerant with sealant in it. I believe the charge capacity is 1.63LBS R-134A. Double check the green under hood label. I am suspecting the system is low on charge. Check for oil/dirt build up around the compressor and lines. If all this check out and the Refrigerant pressures look good then run the car hot (20minutes) and pinch off the two inlet heater hoses on the firewall to the heater core. (Two inlets, one outlet.) If this remedies the issue then change the heater valve on the drivers frame rail/firewall.
-Evan