Started knocking even after an oil change and doesnt go away, suggest?

We can't hear the knock, It would only be a guess. Take it to a service center near you and ask them what it might be, then get a second opinion.

AGREE WITH BOTH#1 AND 2

Please confirm that the correct oil was used and that it is at the proper level. A technician may offer try an engine treatment. Be very clear on all the information for the vehicle so they can accurately diagnose your noise.