What is the cause of a rattling noise in my Audi A2's engine?

I have noticed a rattling noise coming from my Audi A2's engine. It seems to be more prominent when the car is idling or accelerating. What could be causing this and how can I fix it?

The rattling noise could be caused by a loose heat shield in the exhaust system. I would recommend taking your car to a mechanic to have it tightened or replaced if necessary.

Another possible cause could be a worn or damaged timing chain. This is a more serious issue that requires immediate attention from a professional mechanic.