Why is my Audi engine making a squealing noise?

I've noticed that my Audi engine has been making a high-pitched squealing noise lately. It seems to happen more when I start the car or accelerate. What could be causing this and how can I fix it?

This could be caused by a loose or worn out fan belt. It's important to get this checked out and replaced if necessary as it can eventually lead to engine overheating.

Another potential cause could be a faulty tensioner or pulley. This would need to be replaced by a mechanic to resolve the issue.