Why does my Audi A2's engine make a knocking noise when idle?

I've noticed that when my Audi A2 is idling, the engine makes a consistent knocking noise that seems to get louder and faster as I rev the engine. What could be causing this and is it something I should be concerned about?

It's likely that your Audi A2's engine is experiencing a form of engine knock, which can be caused by a few potential issues. Firstly, check your spark plugs and ignition timing to ensure they are working properly. Additionally, it could be a sign of a dirty air filter or low-quality fuel. If the knocking persists, it is best to take your car to a mechanic for further diagnosis.

I've had a similar issue with my Audi A2 and after some experimenting, I found that using a higher octane fuel helped reduce the knocking noise significantly. This could be a quick and easy fix for your engine's knock as well.