Why is my Ford Focus's engine making a knocking noise?

I noticed that my Ford Focus's engine started making a knocking noise. It sounds like it's coming from the front of the car. What could be causing this and how can I fix it?

It sounds like your engine may have a problem with its pistons or connecting rods. I would recommend taking it to a trusted mechanic for a diagnostic and possible repairs.

I had a similar issue with my Ford Focus and it turned out to be a loose spark plug. Make sure to check your spark plugs and tighten them if needed.