The timing belt connects the crankshaft to the camshafts and controls when valves open and close. A loose or worn belt will cause ticking or rattling noises, poor engine performance and overheating, usually triggering the Check Engine light. If the timing belt breaks, the engine canâ€™t run (and on some engines it will cause internal damage). Most engines have timing chains, which typically donâ€™t require replacing. Timing belts, though, often have a recommended mileage for changing. On some engines, itâ€™s as soon as 60,000 miles. On others it can be 100,000 or more.
Original post by Cars.com.