Why does my Audi A2's engine make a loud rattling noise?

I've noticed that when I start my Audi A2, the engine makes a loud rattling noise for a few seconds before it settles down. What could be causing this issue and how can I address it?

The most common cause of a loud rattling noise in an Audi A2's engine is a worn out timing chain. It is recommended to have the timing chain replaced as soon as possible to avoid further damage.

Another possible cause could be a faulty valve lifter. This can be addressed by taking your car to a trusted mechanic and having them inspect and potentially replace the valve lifter.

It is also important to regularly check and change your engine oil and filter to prevent any buildup that could cause engine noise. Make sure to follow your car's recommended maintenance schedule.