Why is my Ford Focus making a strange noise when I turn on the engine?

I recently noticed that whenever I turn on my Ford Focus, there is a strange whirring noise coming from the engine. It seems to be getting louder over time. What could be causing this and should I be concerned?

It's important to address any unusual noises coming from your car's engine as soon as possible.

It could be a sign of a worn out serpentine belt or a loose pulley, both of which should be checked by a mechanic.

Don't ignore strange noises, they could lead to bigger and more expensive problems if left unchecked.