The vlave coves are corroding or swelling at some edges and also where all the ignition coils get screwed to on the cover, causing the screw to loosen and the coil to be loose and causing bad spark function and misfires. Did a temporay fix by mixing epoxy and attaching the broken parts where the screws are screwed on, or forming a epoxy block, then drilling a hole to use a screw and nut to keep the coil firmly in place. The best fix would be to replace the valve covers.