I had the belf off of my supercharger tonight and I noticed some give between the pulley and the internal mechanisms. You can feel it spin a few degrees around then lock up with everthing inside. Once it is up against the internals it spins fine. Is this play in the pulley something to worry about?

Having some backlash is good, by design. How much is normal, I don't know. We could do a comparison between our two cars if you wanted.

Does your supercharger have a rattle sound at idle only?

yup, it has been doing that for a long time, never getting worse as far as i can tell.

Sounds like the coupler. The easiest and cheapest thing to change. I think zzperformance sells them for the M62 cheaper than anyone. A better coupler, too.

http://www.zzperformance.com/zzp/pro...sc_coupler.htm

Fits both the M62 and M90.

I agree. It'* probably the coupler if it only does it at idle.

I've got a new pulley from Pulley Boys I was getting ready to install. Mine is making that same noise at idle as well. Sounds like I should replace this as well.