Why is my Audi 80's engine revving at idle?

I recently noticed that my Audi 80's engine is revving quite high while at idle. It used to be smooth and quiet, but now it seems to be running too fast. What could be causing this issue and how can I resolve it?

It's possible that your idle air control valve is malfunctioning, causing the engine to run at a higher speed than usual. You can try cleaning or replacing the valve to see if it helps.

Another potential cause could be a vacuum leak. This can occur when a hose or gasket is damaged, causing air to enter the engine and disrupt the idle. Check for any visible leaks and have them repaired as needed.

In some cases, a dirty or faulty mass air flow sensor can also lead to high idle speeds. Try cleaning the sensor with mass air flow sensor cleaner, or replace it if necessary.