The timing belt turns the camshaft(s) at exactly half the speed of crankshaft while keeping a precise alignment ensuring that crankshaft will make two revolutions for every camshaft revolution. Every engine has at least one camshaft some have as many as four camshafts. The camshaft causes the intake valves and exhaust valves to open and close in time with the pistons that move up and down in the cylinders. The valves have to open and close at precisely the right time in relationship to the piston movement so that your engine will run properly. If the timing is off engine could blow cause major internal damage. Timing belts can fail without warning, so your only real protection is to change them at your car manufacturer's recommended intervals.

Have You Replaced Your Timing Belt Lately? Most timing belts should be replaced every 50,000 to 60,000 miles. The timing belt is an essential part of the engine. If your timing belt breaks your engine will stop working and could cause major engine damage. Timing belts are not used in all automobiles. The serpentine or drive belts are sometimes used exclusively by a vehicle to provide all the power necessary for its accessories. Other automobiles use a combination of the serpentine belt and drive belts to power vehicle accessories.