Why is my Audi A2's engine producing strange noises when accelerating?

I recently noticed that my Audi A2's engine has been making unusual noises when I accelerate. It's a 2005 model and has been regularly serviced. Any insights on what could be causing this?

It's possible that your engine's fuel injectors are clogged or dirty, which can cause them to make unusual noises. Try using a fuel injector cleaner to see if that helps resolve the issue.

Have you checked your air filter? A dirty or clogged air filter can also contribute to unusual engine noises. Consider replacing it with a new one to see if that improves the issue.