Many of the components in your car use electricity, but there are still many others car accessories that rely on mechanical power. Instead of being operated by electricity, these accessories are run by the accessory belt with the help of the Accessory Belt Tensioner and pulley. These auto accessories include the water pump, the alternator, the steering pump, and some others. They're equipped with a pulley through which they're operated by the belt, and the belt's tension is maintained by the tensioner. Is belt tension that important? It is. Proper tension is necessary so that the auto accessories can be operated efficiently and at the right timing. If the tension on the belt is too little, the belt becomes slack and it may slip. When this happens, the various auto accessories will stop working (think of the failure of the water pump, for instance, which can cause engine overheating). Meanwhile, too much tension can damage the belt prematurely and the accessories that it drives because of overload. How can you tell when your car's Accessory Belt Tensioner is damaged? The first indications are unwanted sounds-rattling noise when accelerating, inconsistent humming sounds, and squeaking when shifting gears. Another symptom is oil leak in the area of the camshaft or crankshaft. The last indication is difficulty in accelerating. If you notice any of the mentioned symptoms, have the Accessory Belt Tensioner checked. If you find it damaged, replace it immediately. Check out Car Stuff for your needed replacement.