Quote Originally Posted by CBC
Thanks for the help. I ordered a new valve today and hope it will solve the problem. Hope to make the repair by mid-week. Did you also replace the "auxillary pump" pn your BMW, along with the valve? I found some info on this website about replacing the valve and it referred to an auxillary pump that is attached to the valve.
The aux pump primarily get warm coolant to the heater core quicker so that you have heat in the cabin sooner. Nice feature in cold climates, but certainly not necessary elsewhere. Not sure about the "cold", "cool" vent issue, whether there are stepper motors controlling the center vents separately or not. Of course, you've messed with the airflow vent "wheels" to rule that out? Also, my car has a center "mixer" that apparently controls or finetunes the amount of cold vs. warm air coming out the vents. I don't notice much difference though. Sounds like the water valve replacement did the trick, though!