I'm working on a 98 contour with the 2.5 duratech, the owner said it just stopped running one day while driving so they had it towed and it has set in their driveway for about 2 years. I put a battery in it-changed the plugs-(they were fouled bad) put the plug wires on correctly-(had four wires crossed up) and finally got it started.now it has a knock in the top end. any thing special with these motors i should know about or look for. I'm planning to tear the valve covers off monday? any suggestions on what I might find?