BimmerFest BMW Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
When I turn both zones up to 84 deg (max), and blower all the way up the driver side is blowing cool & passenger side blowing warm.

A couple weeks ago, I did replace my coolant expansion tank. Drained the coolant and filled with new.

Air caught in the lines somewhere?

BMW X5 e70 35i



Sent from my iPhone using Bimmerfest mobile app
 

·
Nuclear engineer
02/2012 X5 35d M57Y CPO 99K miles NOKIAN WR G3 12K miles
Joined
·
17,538 Posts
Nope. Assymetrical heating suggests failed Hot-water Control Valve - HCV.

IHKA is a hot-water temperature controlled system. The AC / evaporator is ALWAYS fully loaded (unless compressor overrriden off) and the temperature is controlled by IHKA ***8216;computer***8217; controlled HCV.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #3
Nope. Assymetrical heating suggests failed Hot-water Control Valve - HCV.

IHKA is a hot-water temperature controlled system. The AC / evaporator is ALWAYS fully loaded (unless compressor overrriden off) and the temperature is controlled by IHKA ***8216;computer***8217; controlled HCV.


Thanks Doug,

Is that the same as Heater Control Valve?


Sent from my iPhone using Bimmerfest mobile app
 

·
Registered
Joined
·
7,517 Posts
Before looking for faulty parts, did you check the driver and passenger vent settings in the idrive menu?
 

·
Registered
Joined
·
12 Posts
Discussion Starter #6
So I adjusted the idrive settings and seemed to work for a short time. I plugged in my Carly and there’s no error code for HCV.. stumped


Sent from my iPhone using Bimmerfest
 

·
Nuclear engineer
02/2012 X5 35d M57Y CPO 99K miles NOKIAN WR G3 12K miles
Joined
·
17,538 Posts
So I adjusted the idrive settings and seemed to work for a short time. I plugged in my Carly and there’s no error code for HCV.. stumped
Pretty sure HCV is dumb and can’t generate a code.
 

·
Nuclear engineer
02/2012 X5 35d M57Y CPO 99K miles NOKIAN WR G3 12K miles
Joined
·
17,538 Posts
Your IHKA generated a code. The HCV is merely PWM solenoids.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #12
So.. one more question, is the Hot Water Control Valve the same as the Heater Control Valve?


Sent from my iPhone using Bimmerfest
 

·
Registered
Joined
·
3,377 Posts
Driver side blowing cool & passenger side blowing warm

Doug is the IHKA guy but from what I understand, you can always unplug the connector to the HCV. It is designed to need power to close. If unplugged you should have max heat in all vents because it will be open. If it does give you high heat in all vents when unplugged then it should mean it is working. If air stays cold on one side as you describe it I believe that points to the HCV being bad.


Sent from my iPhone using Bimmerfest
 

·
Nuclear engineer
02/2012 X5 35d M57Y CPO 99K miles NOKIAN WR G3 12K miles
Joined
·
17,538 Posts
I believe that the HCV is normally open NO powered shut with PWM variable duty cycle. There are pictures here on BF of dissected HCV.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #17
Yep, so I unplugged the HCV and it’s still blowing cool air. Must be the issue. Thanks all!!


Sent from my iPhone using Bimmerfest
 
1 - 17 of 17 Posts
Top