Why Timing Belts Need Replacement What is a Timing Belt? Timing belts have replaced timing chains on many of today's engines.  Both belts and chains ensure that crankshaft, pistons, and valves operate together in proper sequence.  Belts are lighter, quieter, and more efficient than chains. Why Replace the Belt? Like other components, timing belts wear out.  Proper maintenance requires belt replacement at regular intervals--before they break. Where are Belts Located? Timing belts are on the front of the engine protected by a plastic or metal cover. When Should Belts be Replaced?     ==>MAZDA     HONDA    ACURA When a timing belt breaks, the engine stops.  Replace belts before this occurs.  See recommendations for your vehicle. How Do I Know if My Car has One? Your vehicle manual may tell you, but you should ask your technician--he or she will know for sure. What is a "Free-Running" Engine? If the timing belt breaks on a free-running engine, the engine stops and you will need a tow to the repair shop.  No mechanical damage occurs and the installation of a new belt is usually all that is need to get you on your way. What is an "Interference" Engine? If the timing belt breaks on an interference engine, mechanical engine damage occurs.  It most commonly involves open valves being struck by pistons, resulting in the need for expensive repairs.  In extreme cases, a replacement engine may be required.