I've noticed for about 2 months or so now every time after I turn my car off I can still hear this sound coming from under the hood. It sounds like a fan, or something to cool off the engine, but scince the car is off, why would it need something to cool the engine? What exactly is this and what does it do? I havn't heard anyone else talking about it. I hear the sound every time I turn the car off, where the car is on long enough for the engine to get up to decent temperatures. Anyone know what I'm talking about?