X61 fan clicking at low RPMs

[mfbernstein]

The CPU fan in my X61 has been making a low pitched buzzing sound at most RPMs. I figured it was a bad bearing and ordered a replacement on eBay (non-OEM, but a fan is a fan, right?). I've installed the new fan, and at medium and high RPMs it works great. At low RPMs, it makes a loud clicking noise though. It almost sounds like it's striking the edge of something.

Anyhow, before I go out and buy another one, I'm wondering if I just got a bad fan, or if I somehow messed up the installation.

[raket]

I Have the same problem on my X60