Why does the engine of my Audi A1 make a rattling noise on cold starts?

I recently purchased a used Audi A1 and noticed that when I start the engine in the morning or after it has been sitting for a few hours, it makes a strange rattling noise for a few seconds. What could be causing this and is it something I should be concerned about?

Most likely, this is just a normal occurrence with Audi A1s. The rattling noise is caused by the engines' high pressure fuel pump building up pressure before starting. While it can sound alarming, it is not harmful to the engine and will not affect performance.

Make sure you are using the recommended fuel for your Audi A1. Using lower quality fuel can cause the engine to make odd noises and could potentially lead to damage.