Why is my Ford Focus making a weird noise when I accelerate?

I have a 2009 Ford Focus and recently noticed a strange noise coming from the engine when I accelerate. It almost sounds like a knocking sound. Is this something I should be worried about?

The knocking noise could be caused by a few different things, but one of the most common reasons is a worn out serpentine belt. It's important to get this checked out by a mechanic, as a worn out belt could lead to more serious issues down the road. Have a trusted mechanic take a look and replace the belt if needed.

I had the same issue with my Ford Focus and it turned out to be a problem with the spark plugs. Make sure to get them checked and replace if needed. It's a fairly easy fix and should eliminate the noise.

Another possible cause for the noise could be a faulty fuel injector. This can cause a knocking sound when accelerating. Get it checked and replaced if necessary.