Blower fan noise

[hufhouse]

This is odd. We are getting a noise from our heater/AC fan in the front dash that sounds like it is rubbing or scraping against something internally.

It happens when we brake, and generally goes away when we accelerate. This leads me to believe that the fan is somehow moving when momentum pushes it forward. Or, something is moving into the fan.

It only happens on the lowest two fan speeds. It doesn't happen at the higher fan speeds.

I removed the fan yesterday, and I found a piece of debris (a maple tree "helicopter") in the fan. I removed it, and felt all around in the area where the fan sits. I couldn't feel any other debris or anything loose.

The fan assembly seemed quite solid...no loose parts and it wasn't wobbly on the spindle.

I reassembled everything tightly, and the problem is still there.

Any ideas?