Why is my Audi A4's engine producing a rattling noise?

I have recently noticed that my Audi A4's engine has been making a loud rattling noise while idling. It stops when I accelerate, but then returns when I come to a stop. What could be causing this issue and how can I fix it?

It is possible that the rattling noise is coming from a loose heat shield on your exhaust system. This is a common issue in Audi A4s and can be fixed by tightening or replacing the heat shield.

Another potential cause of the rattling noise could be a faulty engine mount. If the mount is worn or damaged, it can cause the engine to vibrate and produce a rattling noise. It is important to get this checked and replaced by a mechanic to avoid further damage to your engine.