When your vehicle is moving at 30 MPH or more, air is flowing through the Condenser coil, mounted in front of the radiator, WITHOUT the Radiator Fan operating. When the vehicle is stationary, the Radiator Fan (E-fan) MUST run or the refrigerant pressure gets too high and the compressor valve is turned OFF, preventing compressor "Pumping" of refrigerant (R-134a).
When compressor valve shuts off compressor "Pumping", there is NO cooling by the Evaporator coil located in the center dash area. The Blower motor still operates, but the air temperature and humidity increases.
There are other possible causes of intermittent compressor operation, or changes in "Mixed Air Flap" Positions which can cause lack of cooling, but the FIRST thing to check is Radiator Fan operation with Compressor Valve activated (Green LED on "Snowflake" button lit). That button is on the right side of the A/C Control Panel.
On my 2007 328xi, when I do cold start at ~ 70F, with thermostats set to 65F, the Radiator Fan starts to run after 30 to 45 seconds, at ~ 20% to 40% of max speed, NOT howling, but you can see it run with hood open, and feel air draft above fan shroud.
So checkRadiator Fan operation at cold start with vehicle stationary and hood open, A/C on and Compressor Valve activated. Let us know what you find, and if the fan is running, but your are NOT getting cold air at idle, post back and answer the questions below.
BTW, there have been Several reported cases of Radiator Fan power supply being INCORRECTLY disconnected in the Blower Motor Harness replacement recall. The Red/Blue or Red/Violet power supply wires related to the Blower & E-fan CAN be confused by a tech, even though they are on different connectors on the firewall side of the JB (Junction Box) Fuse Panel, which must be removed as a part of the Recall Procedure. So if your current issue began AFTER that recall, and your E-Fan NEVER runs, that is a likely cause.
Obviously, Engine OVERHEATING if stationary more than several minutes will ALSO occur if your Radiator Fan is NOT working, so monitoring ECTS (Engine Coolant Temp Sensor) signal as received by the DME (Engine Control Module) is quite helpful.
If you post back, please provide the following info, as diagnosing the refrigeration system (Compressor Pumping of R-134a refrigerant) require at a MINIUMUM, a Can Tap with a gauge ($15 to $20 Amazon), or preferably a Manifold Gauge Set, to measure both "High & Low Side" pressures ($25 to $35 Amazon). If you take an hour or two to understand how auto refrigeration systems work and invest $25 to $50 in basic equipment, you can save yourself a LOT of Time & Money.
Questions:
1) What are the Last-7 characters of your VIN? Needed to provide correct ISTA wiring diagrams.
A444008
2) Do you have ANY type of A/C Gauge, either a Can Tap with Gauge or Manifold Gauges?
i can get them
3) Do you have any type of Scan Tool to read Fault Codes or view Live Data, and if so, the make & Model?
not yet, but seems im going to need them
4) Do you have INPA or ISTA (BMW Diagnostic Software -- Free Download)?
5) Do you have a Windows 10 OS Laptop? If so, $45 BimmerGeeks K+DCAN cable is ONLY expense (other than several hours of your time ;-) to get CORRECT diagnosis of most any fault in your vehicle.
yup, have a windows laptop, not much memory though
Don't feel like it's ALL JUST TOO MUCH.
We can walk you through how to use INPA to view Live Data of Refrigerant Pressure Sensor signal (High Side Refrigerant Pressure), Evaporator (Cooling Coil) Temperature, Radiator Fan Speed, along with Engine Temperature, Coolant Pump Speed and anything else which MAY be related.
You do NOT need INPA to solve a radiator fan issue, but it is the ULTIMATE tool to diagnose WHAT is happening in a system -- in your case, WHAT changes when your vehicle comes to a stop, causing the Compressor Valve to de-activate. It shows you "Live Data" on your computer screen, seated in the Driver Seat, all from simply plugging into the OBD II Socket.
George
