Why does my Audi A6's engine make a strange knocking noise?

I have noticed that my Audi A6's engine makes a strange knocking noise, especially when I accelerate. What could be causing this issue and how can I fix it?

Your engine may be experiencing detonation, also known as 'engine knock'. This can be caused by using low-quality fuel, incorrect spark plug timing, or carbon build-up in the combustion chambers. It is important to address this issue promptly to prevent potential engine damage.

You may need to replace the engine's knock sensor, which detects and helps regulate the timing of the engine's combustion process. A faulty knock sensor can lead to engine knocking noises and decreased fuel efficiency.

It could also be due to a problem with your Audi's fuel pump. A clogged fuel filter or failing fuel pump can cause the engine to struggle to draw enough fuel, resulting in knocking noises.