1996 Strange engine noise

Hey guys I have a 1996 Lesabre, recently I have noticed almost like a rush of air sound everytime start up. I cannot pinpoint exactly where it is coming from. I have check all the vac lines etc. It sounds like it might be coming from around the throttle body area. The odd thing is you only hear it when your first start the car. Has anyone else had this problem and could it possiably be the upper plastic intake about to go bad?

tough one here... I would check your ave gas mileage over one tank of gas. if it is below 21 mpg, then its a problem. Also, see if it stops when the idle begins to drop. Is it a "sucking" sound or a "blowing" sound?