Why are there rattling sounds coming from my Audi A4's engine?

I've noticed that my Audi A4 is making strange rattling sounds whenever I start the engine. It only lasts for a few seconds and then goes away. What could be causing this?

It's possible that there is an issue with your engine's timing chain. If it's loose or worn out, it can cause rattling sounds.

Another possibility is that there is a loose or damaged engine mount. This can cause the engine to vibrate and produce rattling noises.