[gurns]

When the inside air temperature in the cabin is warm, such as when the car has sat outside in the heat, and I start the car, the fan blower motor emits a loud hum like noise. The A/C control is set on AUTO. The fan speed function works properly as it increases to rapidly cool down the cabin. As the cabin reaches a cooler temperature the humming sound will subside and eventually disappear. This is not a normal sound profile as the car did not make this noise for the first 5 years I owned the car. I changed the engine and cabin air filters but the sounds still remains. The humming sound will occur if I have the A/C on or off and only goes away when the cabin temperature cools. This problem does not happen when the outside air temperature is cooler than 70 deg F. Any ideas what could be the problem? I read it could be a deteriorating mesh screen filter that is caught in the fan "squirrel cage"? If so, is it possible to clean that debris out with out performing a major operation or is best handled by a dealer? Many thanks for any inputs.