Why does my Audi A1's engine make strange noises?

I recently bought a used Audi A1 and I've noticed that the engine makes some strange noises. It's not a constant sound, but I hear it when I accelerate or decelerate. Is there something wrong with my engine? Should I be worried?

The strange noises could be caused by a variety of factors such as worn out belts, faulty pulleys, or even low engine oil. It's important to get it checked out by a mechanic to determine the exact cause.