Last month I had my timing belt replaced and after the job was done (new tensioners as well) I heard a slight 'whirring' from the engine and a bit more resistance from the engine when I push the throttle.

I took it back to the shop and the mechanic pinpointed the source of the noise - one of the accessory belt roller bearings is going bad he claims.

Two questions:

1. Is there any coincidence that this noise happened right after the t-belt was replaced and

2. Would this be an easy job for a do-it-yourself mechanic?

Another example of why I perform my own maintenance! :o)