Why does my Audi A2's AC blow hot air when the engine is running?

I recently noticed that my Audi A2's AC only blows cold air when the engine is turned off or in idle, but once I start driving the car, the air turns hot. Is there an issue with the AC system or is it a problem with the engine?

It is likely that there is an issue with your AC compressor. When the engine is running, the compressor needs to work harder to cool the air, but if it is faulty, it may not be able to produce enough cold air. It is best to have a professional mechanic inspect and possibly replace the compressor.

Another possible cause could be a faulty AC relay. This is a small component that controls the function of the AC compressor. If it is not working properly, it could be causing the hot air issue. Have a mechanic check and replace the relay if needed.