Timing Chain and Timing Belt Problems and Repair Demonstrated by Mechanics
Here’s an informative guide that will answer many of your timing chain questions: What is a timing chain and how does it work? Which is better---a timing chain or a timing belt? Should timing chains or belts be serviced/replaced periodically to prevent catastrophic engine damage? Will a broken timing chain or belt always result in a damaged engine? What does it take to replace a timing chain or belt and how difficult is it?
Source: torquenews.com