the last few days the blowers in the car have been intermitent, they will work for a few minutes then you get a whirring noise, sounds like a blockage and the flow of air stops or slows greatly, usually a few minutes later they return to normal, could this be the blower motor on its way out and packing up ??

thanks

Blocked pollen filter maybe? The air care could be switching from fresh to recirculated air automatically.