1999 Ford Escort Loud Engine Noise

My daughter drove home, about 20 miles, and the car drove and sounded normal. After setting for about 3 hours she attempted to start the engine and it sort of started, but made a loud clanging noise. We let the car set overnight and I checked the oil level which was normal, and didn't notice any leaks or other visual problems. I removed the valve cover, thinking it may be a loose valve tappet, but after checking all, couldn't find any unusual looseness. I had my wife turn on the key and try to turn over, but not start the engine to visually see the tappets. The engine wanted to start, but still there was a loud clanging noise. I have changed timing belts on my older 93-94 Escorts, but when they were out the engine just turned over easily without any noise, but wouldn't start. I can't believe a rod came loose while setting, but could some of the valves been bent on this non interfering engine. Do you have any suggestions.