Why does my Audi A5's engine make a whistling noise?

I recently bought a used Audi A5 and noticed that the engine makes a high-pitched whistling noise when accelerating. Is this normal or is it something I should be concerned about?

It is not normal for an Audi A5 engine to make a whistling noise. It could indicate a problem with the turbocharger or a vacuum leak. You should take your car to a mechanic for a proper diagnosis.

I had the same issue with my Audi A5 and it turned out to be a loose intake hose. Make sure to check all the hoses and connections under the hood.

I also experienced the whistling noise in my Audi A5 and it was due to a faulty throttle body. It's a common issue with this model, so I suggest getting it checked by a mechanic.