Why does my Audi A4 engine make a squealing noise?

I recently noticed that my Audi A4's engine makes a high-pitched squealing noise when I start it up. It goes away after a few seconds, but it's concerning. What could be causing this?

It sounds like your serpentine belt may be worn out and needs to be replaced. This belt helps power various components in your engine, including the alternator and water pump. If it's loose or damaged, it can cause squealing noises. I recommend taking your car to a mechanic to have it checked and replaced if needed.

Another possible cause could be a faulty tensioner or pulley. These components help keep the belt at the correct tension, and if they're not working properly, it can cause the belt to slip and make noise. I suggest having a professional inspect and replace these parts if necessary.

It's also possible that the noise is coming from a malfunctioning accessory, such as the power steering pump or air conditioning compressor. I recommend having a mechanic inspect and repair any faulty components.