Why is my Audi A2 engine making a loud knocking noise?

I've noticed that my Audi A2's engine has been making a loud knocking noise recently. What could be causing this issue and how can I fix it?

The loud knocking noise could be due to a lack of proper lubrication in the engine. Make sure to check and replace your oil regularly to avoid this issue.

Another possible cause of the knocking noise could be worn out engine bearings. If this is the case, it's important to get this fixed as soon as possible to avoid any further damage to your engine.