535xi A/C Problem
 

Hello,
I'm having a A/C Issue i'm trying to tackle. When i first turn the car on my A/C will start to blow cold air. (Driver Side Vents & Floor Vents, Passenger Side Vents & Floor Vents and Middle Vents). When the car gets warm my a/c doesn't get cold as when i first start the engine up.. The Drivers side floor vents will start blowing out hot air and the middle dash driver side will also start blowing warm air. The driver side (close to the door) stays cold & the passenger side middle & floor vents and door will stay cold.

What could be the issue?

Could be a number of things. Possibly heater control solenoid valves letting hot coolant through the heater core when they shouldn't (leaking or sticking).

Are you running the AC in automatic mode? And do you have the center vent setting to full cold in the iDrive screen?

Thanks for the reply!
My knobs for both driver side and passenger side are set to the lowest temp. On the iDrive it’s set to max cold as well.

is there anything else that could affect the a/c besides the heater solonoid?

Can inpa, protools detect solonoids malfunctions?

Have a look here: https://www.realoem.com/bmw/enUS/sho...diagId=64_1481

Checking temperature on hoses 2 and 3 in this link will tell you if the problem is the heater valves. Check when the engine is hot. Those hoses shouldn't be hot if there is no call for heat as there should be no coolant flow to heat them. I believe the valves are open when unpowered, and are pulsed shut to regulate temperature to the heater core, letting in smaller amounts of hot coolant when the duty cycle is low, larger amounts when the duty cycle is high. If they're leaking or not getting power, you'll get coolant flow (and heat) you don't want.

Other possiblities could be steppers and flaps in the HVAC asssembly itself, or a fault in the control unit. Rule out cheap and easy first. If you have access to scantools, you will find error codes for the IHKA if they exist.

If it turns out to be your heater control valve, let me know by PM. I have a used OEM unit that I sourced from ebay and never needed.

edit: I have an 07 530xiT. Check realOEM to see if the part numbers are the same

I have this this exact same issue. I believe it is a heater control valve issue. Each side is controlled individually by the valve. I replaced it today and will be testing it tomorrow. If I forget to respond shoot me a message.

Easy job. Removed air intake and charge pipe then you can access it. Removed the hose clamps with vice grips then a little bit of wiggling got the hoses off. Just make sure you are prepared to catch the antifreeze and refill the radiator with fresh coolant. You likely need a battery charger to make sure that you can run cycle the water pump with engine off (hold down gas pedal for ~30 seconds and heater and fan cranked To high, you should see coolant pumping into coolant reservoir). $60 part on amazon 1 hour work.