Put your hand on the valve you will feel the clicks. Set the temp to auto and say 70F. It should click every second or so

I have read other reports of how little coolant is lost during heater control valve replacement.

I have also read about durability problems with non-OEM replacement valves. I just rebuilt an OEM valve with $30 worth of new seals from Ebay. I suggest you rebuild yours as a spare. If you do, be sure to match up the specific part number as there are different seal kits.

I plan to install my rebuilt OEM valve and replace the aftermarket unit my car came with. I am getting uneven heat from the aftermarket unit.

It's at the very top of the coolant system. Similar when changing the aux pump I only had to left the hoses a couple inches and stop any coolant


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Well, there was no change after swapping the heater control valve for a new unit. Still cold in the driver side for all vents. Now what?


To recap:
*watched the climate control system in INPA in real-time: both heater cores read the same temperatures
*unplugged the heater control valve and nearly melted to death while driving; driver side was super warm
*the OEM unit nor the new unit have changed the cold driver site temperatures

Sounds like you are getting outside air always but somehow only on the driver's side.

In my testing at steady state the heater cores should be between 130-150F.

If that is the case the problem lies within the dusting.

I think if you pull the MID you can get pretty good access to the Bowden cables and determine which one/s aren't doing their job.

Are you running your system on full auto and does the fan speed adjust appropriately when the overall cabin temp hits the set temp?

I'll do that: Pull the MID and observe. To answer your questions, I have never utilized that auto feature for the climate control nor have I paid attention to listen to fan speeds change. However, the fan speeds DO change when set on auto.


I wonder if there's a dead Audi that crawled into the left blower and died or something, blocking the heat. :rofl:

The best possibly only way to know if the HVAC is working properly is set it to auto. Set to a level of say 70F. When cold the fan should blow pretty hard maybe 2/3 and drop down to a very low speed when close to set temp.

Check the system temp regulation by bumping the temp below cabin temp once it is at steady state. Eg. Bump temp to 65 once it's gotten to 70. The fan speed should rise and the vent output should get cold . Then bump up the temp up to say 75, the fan should drop to very slow and then quicky speed back up as the set temp gets farther from actual temp.

See if, when letting the automatic do its job you are still.getting the mismatch of temps left and right and plan to dig into the dash via the MID. I'm betting a cable or the control for it is broken.