[v1valarob]

As you can see in my previous thread, my tension belt shredded. I found it before it completely snapped. The belt was replaced.

http://www.e90post.com/forums/showthread.php?t=1146112

After replacing the belt I noticed a very strange sound. I dropped it off at the dealership yesterday. Just got word that they cant find the problem. They did say the technician acknowledges that there is a "noise." But with no codes or driving issues, they cant find anything mechanically wrong.

Anyone here have any idea??

[stewey]

I'm surprised they didn't find the source. I wonder if they really tried. If you remove the belt, and run the engine does the sound go away? While the belt is off, spin all the pulleys and check for play and or raspy feel. Good pulleys will be buttery smooth and will stop rolling almost right away. You can also take a long metal bar like a breaker bar and put one end to your ear while probing different spots on the engine (avoiding moving parts of course). Try to isolate the source that way.

[v1valarob]

Removed the belt today to see if the vibration would go away, and it did. I've installed, removed, and re installed this belt over 5 times now to verify I've fitted it correctly and the noise stays. At this point I'm going to order another belt. Maybe the Napa belt is slightly defective in size or tension?

I replaced the idle pulley myself yesterday and that did nothing.

Edit: Looks like it may be the alternator pulley. Any suggestions on where to purchase a new one?

[v1valarob]

So the sound is back. I can only assume its the alternator pulley again. Anyone else have this happen to a new pulley within a year?!