How do I fix the rattling noise coming from my Audi 80's engine?

I've noticed a rattling noise coming from my Audi 80's engine when I first start the car. It goes away after a few minutes but it's still concerning. What could be causing this and how can I fix it?

It's possible that there is an issue with your engine's timing belt or tensioner. It's important to have this checked and replaced if needed, as a broken timing belt can cause major damage to your engine.