I suspect this is the cause of the whining noise i hear under light load. I was thinking about bypassing it with a short belt for the winter (which would also tell me if it was the cause of the noise) and replacing it if the noise went away, but most people who responded to this thread said it was a waste to go that route, so now I'm thinking I'll just replace it.
Is it easy to replace an idler pulley?
Is it easy to replace an idler pulley?
