I Hate To Sound Like The Dealer But......they All Do That. At Least The 3.0 Its A High Pitched Whine Or Whistle That Sounds Like Its Coming From Under The Vehicle. Only Happenes Under Light To Moderate Acceleration Right? I Think It Might Be The Fuel Pump Or The Transfer Case. In Any Event, All Of The 3.0 Vehicles Ive Driven (loaners, Test Drives, Ect.) Exhibit This Behavior..........fraankie P.