I have a noise that sounds like a loud ratchet coming from the engine in my Cavalier 2.0 GLi 1991. Knocking gets louder on the move. Power varies from normal to 70% at different times; both with the knocking. Oil is ok and I've changed plugs and leads.
check the power steering. full lock then move forward slowly . common problem on the old cavs. if it gets worseon full lock you need a new steering rack.