Audi A4 air-con issue

djpm

I have an 03 A4. There's always been an issue with the heating/aircon (have it 4 years). If I set it to 18 degrees (or any temperature other than "low"), it just keeps heating. I don't do that much mileage so it doesn't bother me an awful lot, but I'm thinking of selling it so I'd like to sort it out.

One other issue (whether related or not) is that when you turn off the ignition, you can hear whirring and clicking behind the dash, as if there are motors running and moving things. I assume these are the blending motors.

Another thing which may or not be related is that the outside temperature display reads several degrees below the actual temperature. It could be raining and reading -6 degrees.

I've brought it to an Audi dealer (in the West) and a good(ish) independent mechanic and neither could solve it.

I know of a couple of others that have had this problem. One guy I parked beside on the street said he had the compressor replaced but it didn't solve it.

Any ideas?

Anan1

Might it be the cabin temperature sensor? Have you tried hooking it up to VAG-Com?

al2009

Get them to change the outside temp sensor, if it's climate control it looks at outside temps to decide whether to bring in fresh air to cool cabin, as alan says the cabin sensor is probably faulty and this is why it heats to bring the temperature to setpoint.