Why does my BMW Z4's engine rattle at idle?

I recently bought a used BMW Z4 and I've noticed that the engine tends to rattle when idling. It seems to go away when I rev the engine, but it's still concerning. What could be causing this and what should I do?

It's possible that the timing chain tensioner is worn out and needs to be replaced. This is a common issue in BMW Z4s and can lead to a rattling noise. I would recommend taking it to a trusted mechanic to have it checked out.

Another possibility is that the engine mounts are worn out and causing the engine to vibrate more than usual, leading to the rattling noise. It's important to have this checked and replaced if necessary to avoid any further damage.

I would also suggest checking the oil level and condition. Low oil levels or dirty oil can also cause rattling sounds in the engine. Make sure to follow BMW's recommended oil change schedule and use high-quality oil to avoid any potential issues.