Video Card Fan Vibrating?

Hey Logan, Wendell, Qain, Pistol, and the rest of the Tek Syndicate community :)

 

I have a Sapphire HD7870 GHz Edition that's about 4 months old and it recently started making some weird noises.  In games when the fan starts spinning fast, there is a weird vibrating noise that comes from the video card (I can't really describe it, so if need-be I'll take a video of it).  

Anyway, it seems the problem only occurs when the GPU is within a certain load and fan speed range.  In Furmark, the noise will be present for about 10 seconds, but once the load reaches 100% and the fans reach higher speeds, the noise disappears.  Also note that I can't recreate the sound just by raising the fan speed in MSI Afterburner.

Last night I opened my case while gaming to try and find a solution.  Pressing on the plastic housing around the fan stopped the noise.  Then the second I removed pressure, the sound started again.

Is this a problem I should be concerned about?  Like the fan hitting something?  Or is the noise just plastic vibrating?

Thanks!