Why does the ford explorer make a howling noise?

Both V6 and V8 Ford Explorer engines from various years sometimes experience a very loud low pitched moan or howl that sounds as if it is coming from the air intake area. The culprit is the Idle Air Control Valve. (I.A.C.). It is possible to remove and clean the IAC with the proper care but it is not advised to do so. Although it may work for a short time, it will eventually fail again and possibly force You to call a towing service when You least expect it. Price for the IAC varies from $70 to $120 for V8 and $30 to $80 for V6 models. This repair will usually take around ten minutes.