Idler pulley/auto tensioner pulley squeal-identification

[bdavis007]

2006 M45

I have a loud squeal at start up and idle so I bought belts and an idler pulley to replace everything.

I identified the pulley that was making the noise, which I thought was the idler pulley......but the replacement does not fit, the inside diameter of the bearing is too big. The pulley I am referring to is on the right side on the engine if you are looking at it.

Is this the idler pulley or Engine fan cooling pulley? Please confirm, the gates replacement I have does not fit.

Is this what I need "A/C Drive Belt Idler Pulley Goodyear 49192"

Anyone seen this?

[Ilya]

I believe that is the A/C one...cause the left one is the alternator, middle on is the main pully, and the other one with the a/c and accessories pully.