I'm thinking my problem is one of these 2 valves (air change-over valve or cut-off valve), but I'm not exactly sure:
http://www.renntech.org/forums/index.php?showtopic=1132&hl=
Your problem is sounds for sure like the bearing in the pump, the pump's don't look hard to take apart, only 5 or 6 torx holding it together, and 3 #10 bolts and 2 wires plugged into the car. I took it out in about 15 minutes today (as it didn't fix my problem), the shop I had originally taken it to to have it installed charged me for 1.5 hours, so I'm assuming their 4 hours to take the intake off is over rated. I'm also wondering if I'll need new gaskets for the intake if I remove it to change this valve, and what the torque specs are...
My original pump makes that noise occationally, but it is only once a month or so, and it only lasts a minute or so, so I'm not too concerned about it.
My offer still stands for $200 shipped if you can't replace the bearing & you want to buy the other pump off me..
Thanks for the input guys, I really appreciate it!