I could not find a good picture of a V8 engine from bmw so I will assume this will still work. I found a picture of an N52 I6 engine and I am wondering if someone could label the pulleys. I color coated them. My car had a problem I just found out with the purple dotted one (I think). I am guessing that is the idler pulley? I am just tryin to understand which different pulleys are and do.

If it is the idler pulley or whatever pulley it is, what would cause the belt to run not square on this pulley. Mine was riding about a quarter of an inch off center twoards the front of the car-but otherwise spinning fine without wobble. I did have a nasty "gargley" sound with accelration only and beginning to wonder if this had somethin gto do with it. It is bein replaced but I want to make sure I know the CAUSE of why this happened and just not to fix the RESULT of a worse or underlyin gproblem by them replacing the pulley only for it to have something go wrong again.

thanks so much!

 

Pic converted to .jpg for your convenience:

 

Thanks for doing that! Now how about identifying those pulleys!