When fan turned on makes a flapping noise

Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. I'm sorry to hear you're having trouble with your Miata. A flapping noise from the blower motor when turned on usually indicates that something is obstructing the fan. This could be debris, such as leaves or small objects, that have entered the blower motor area. It could also be a problem with the fan, such as a loose or damaged fan blade. In some cases, the issue could be related to the cabin air filter if it's clogged or improperly installed, causing airflow disturbances. If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!