Just finished installing a Panasonic WhisperLite fan and the most annoying thing is happening. Whenever I have the grill in place the fan will sputter, like a playing card stuck in bicycle wheel. Without the grill on the fan, it is as quiet as advertised (and man is it quiet!). Also, if I push the grill over to the side it stops sputtering, but slowly slides back and starts up again. It sounds like the blade is hitting the plastic case/housing.

I should note, Panasonic's tech support was zero help, they told me to take the housing apart and inspect it. As I'm not a fan technician, I would have no idea what to look for. I also haven't installed the duct work yet, waiting until the fan is in working order.

Any ideas?! I am really dreading another day spent in my attic rolling around in 60 year old blown in insulation.