Why is my Audi A6's engine making a high pitch noise?

I recently purchased an Audi A6 and I've noticed that the engine has been making a high pitch noise. It's not incredibly loud, but it's definitely noticeable. What could be causing this and should I be concerned?

It's possible that your Audi A6's serpentine belt is worn or loose. This can cause a high pitch noise coming from the engine. I would recommend taking your car to a mechanic to have them inspect the belt and replace it if necessary. It's important to address this issue as a worn serpentine belt can lead to bigger problems down the road.