Why is my Audi A4 making a strange noise when I accelerate?

I recently noticed that whenever I accelerate in my Audi A4, there is a strange noise coming from the engine. It's not very loud, but it's definitely noticeable. What could be causing this noise and should I be concerned?

From my experience, it could be due to worn out engine mounts. As your car gets older, these mounts can become less effective at dampening engine vibrations, resulting in strange noises.

It's possible that your air filter is dirty or clogged, causing the engine to work harder and produce more noise. Try replacing the air filter and see if the noise improves.