Why is my Audi 80's engine making knocking noises?

I recently purchased a used Audi 80 and noticed that the engine makes a knocking noise when I accelerate. It doesn't happen all the time, but it's concerning. What could be causing this issue?

It's possible that your engine's spark plugs are worn out or dirty. This can cause a knocking noise and decrease engine performance. Consider having them replaced or cleaned.

Check the oil level in your engine. Low oil could be causing the knocking noise, as well as potential damage to internal components. Make sure to maintain proper oil levels for optimal engine performance.