What is the cause of the strange noise in my Audi A5's engine?

Recently, I noticed a strange noise coming from my Audi A5's engine while driving. It only happens at specific speeds and seems to go away when I accelerate. What could be causing this issue?

It is likely that your engine is misfiring. This can be caused by a variety of issues such as faulty spark plugs or a clogged fuel injector. It is important to have a mechanic diagnose and fix the problem to prevent further damage to your engine.

Based on your description, it sounds like your alternator may be failing. This can cause strange noises and fluctuations in your car's electrical system. It is best to have it checked and replaced if necessary by a certified mechanic.