When an idler pulley fails, it is usually the bearings that go bad, though it does little more than track the belt. A failed roller can cause excess noise and, if not spinning properly, the relay roller can cause the belt to wear and break prematurely. Replace yours at the first sign of wear to keep the timing belt operating on track.
If performing the timing belt service on your engine, be sure to replace the relay roller as well as other vital components that ensure you get the full life out of your timing belt. Check out the rest of ECS Tuning's Timing section and have everything delivered to your door.
