The tensioner acts on the timing belt or timing chain of the engine and plays the role of guiding and tightening it so that it is always in the best tension state. The tension of the timing belt and timing chain can be adjusted automatically.
Driven by the timing belt or timing chain, the camshaft drives the valve to open and close at the correct time, and cooperates with the piston to complete the four processes of intake, compression, power, and exhaust. Because the timing belt and timing chain will jump when running at medium and high speeds, and the timing belt will be stretched and deformed due to the material and force of the belt in long-term use, resulting in inaccurate valve timing. As a result, it will cause failures such as fuel consumption, weakness, and knocking of the vehicle. When there are too many jumping teeth, because the valve is opened too early or closed too late, it will also cause the valve and the upward piston to collide and damage the engine.
The belt tensioner pulley is a kind of car tensioner, which is used in the timing system of the engine to adjust the tightness of the timing belt/chain. Once the tensioner is damaged, it will not be able to adjust the tightness of the belt, the engine will make abnormal noises, the timing will jump, and the ignition and gas distribution time will be disordered, which will affect the normal use of the car. Usually, when the timing belt is replaced, the tensioner will also be replaced. After a long time of use, the belt will be stretched, and the tensioner will automatically adjust.