Vehicle engines are precision machinery; the movement of many parts must be synchronized carefully to make the engine perform properly. Intake and exhaust valves are critical components for optimum engine performance. These valves contain mechanisms that must be adjusted correctly to allow for changes in temperature and compensate for material wear. Running a vehicle with incorrectly adjusted intake and exhaust valves can have a detrimental effect on your vehicle.
All of the intake and exhaust valves in an engine must open and close at correct intervals to allow the engine to run smoothly. These valves have a small amount of clearance between the valve itself and the mechanism that activates the valve.