Timing Idler / Tensioner Roller Description
This component is one of the important and consumable parts of a car engine. It consists of a bearing and a plastic roller on which the belt runs. It is usually replaced during timing belt service or replacement.
Failure of this component can cause serious engine damage, leading to timing belt breakage and ultimately bent valves. Early roller failure may result from dust or water ingress, or from engine oil leakage into the timing belt cover.
The first sign of roller failure is usually noise, especially in cold weather. It is recommended to purchase and use a complete timing kit rather than individual components.