I know the cooling fan comes on when the cabin is hot on our 2016 Metris passenger...which is very nice. But, when I stand outside the van while my wife starts the engine, the fan (I think/hope the fan) roars so loudly it's almost embarrassing. Sounds like it's running away, or will fly off at any moment. It stops soon after the van starts moving. Is this normal...or a trip to the service department?