HVAC fan loud noise/vibration on higher settings

[Sella Turcica]

My 03 Camry XLE (with digital HVAC controls) is having an issue. When the heat/AC fan is turned up to the highest two settings, something is making an awful noise and I think it's either the fan going bad or the fan vibrating against something. It is present but not terrible at low fan speeds, it really picks up at the higher speeds.

It's a very low-pitched, loud vibrating/rumbling sound and vibrates the rearview mirror. I can feel it vibrating the dashboard noticeably as well. The air is blowing through the vents just fine.

A couple things I also noticed: No particular setting (vents, temperature, etc) will fix the noise. Sometimes when I accelerate from a dead stop it will slightly change the tone of the fan noise, that's about it.

Anybody know what this might be, or something I can check out/test?

[Sella Turcica]

Wow - you were spot on. I dropped the AC fan, which was ridiculously easy to do, and there was debris in it. Apparently the fan had somehow ingested part of the previous pollen filter and it was off balance. Removal completely solved the problem.