Timing Belt Idler – Important Notes
This component is one of the important and consumable parts in a car engine. It consists of a bearing and a plastic roller on which the belt is mounted. It is usually replaced during timing belt service or replacement. Failure of this part can cause serious engine damage, including timing belt breakage and, ultimately, bent valves. Early failure of the roller at low mileage can be caused by dirt or water ingress or engine oil leakage into the timing belt cover. The first sign of a failing roller is usually noise in cold weather. It is recommended to purchase complete timing belt kits to ensure all components are replaced properly.