High speed fan going out???
My 2004 3.9,v8 LS has developed a high pitch noise when fan switches to high speed. Sometimes as I am driving the noise will subside then get loud again. The fan has not previously been as loud as this. There is no : rattle, light,high temp.or vibration. When I took it to the Lincoln dealer the sound had decreased as it idled awaiting his inspection and seemed normal. Of course as I got further down the road it returned to the high pitch.