My 2004 R53 is making a rattling sound that I think may be coming from the supercharger. It isn't overly loud, and seems to get better after the car heats up. Here is the process that lead me to question the supercharger.

The car has 87k miles on it, so I suspected a possible source of the rattle could be worn timing chain guides. After some research I found that the timing chain guide tensioner was a possible point of failure. So I replaced the tensioner, but no change was noticed to the rattle. I then noticed the belt tensioner has a slight vibration to it when the engine is running. Next step was to take the drive belt off and see if the rattle continued. Without the belt installed the engine runs perfectly smooth and quiet. So that tells me the noise is not timing chain or valve train related. All idler pulleys spin free with no play in the bearings. With the belt tensioner pinned in the retracted position, I could not feel any play in the tensioner assembly. Tensioner damper strut bushings looked ok. Crankshaft balancer had a TINY amount of play that you could barely feel and not visibly see. Supercharger rolled with a little effort, but rolled perfectly smooth. When reversing the direction of the pulley I could hear/feel a distinctive "clink" sound. If you rotated the pulley from one direction to the other quickly it made a "clink-clink" sound every time you changed directions. This is my first experience with a supercharger and I don't have any gauge at to what "normal" is. Is this a sign that it's time for a supercharger rebuild? Is it a sign of low oil level in the supercharger? Or maybe it's the belt damper/tensioner or crank damper pulley? Someone with more supercharger knowledge than me please let me know what's up!

Sorry this got so long, but hopefully if you made it this far you know what my problem may be. Thanks!