Its the alternator.....thats it does it for all of us...it must have something to do with when its under load and at certain rpms.....

 

It pretty much sucks that Ford doesn't take care of this alternator problem. Why is it that so many other vehicles don't have this problem? My battery is over 4 years old so I'm going to replace it with a new Interstate 1000 amp and 850 CCA this week. I'm curious if my battery is causing my alternator to work harder and cause this noise under extreme cold.

 

Crazy stuff, nothing worse than whistles, squeels, squeeks, rattles, shudders, and vibrations. Man that kinda thing drives me crazy.
I will do an alternator swap with my dads 05 to test it before I dish out money for an alternator.

 

alot of 05's had the problem as well....it was a pretty common thing, they'd fix them under warranty...

 

I have 2005 f-150 super crew 4.6 4X4 with now 80,000km. I bought it used last year and I also have noticed this irrtating noise when the temp reaches below -10 and as I pedal the throttle the noise changes pitch. Had it at the dealer last year they couldn't find any codes or reproduce the noise, so they say. I tend to think either cold air coming into the intake or belt or pullies/tensioner. I hope either I or someone finds this problem. I have only ever had Fords ( trucks cars vans) and have never had this problem before. If I find it I will definately let everyone know as I tend to brag my Fords all the time till they hear the noise and I cheapestly say didn't do that before..

 

'04/150/XL, 4.6 L, 12K per year, noted whistling first winter at about 55 mph at 10 degrees or colder and I could modulate the sound by slightly changing the throttle?!

I was shocked as it was a new truck but as soon as the outside temp. rose, the sound went away. I know it was not the alternator because I never did anything about it and the alternator is fine, the truck still runs fine today, and this winter I have yet to hear the noise, four years later.

I think conditions such as relative humidity, temp., dew point, and others I don't know of may contribute to the noise within the intake system. If, however, something breaks and after I fix it the noise never occurs, I'll know what the problem was. Great trucks these Fords, I really have no complaints. I'm 62 and I figure unless it breaks I'm gonna drive, observe it, and when it gets bad, fix it.

Every morning I wake up and ask, "Why me God?, why am I so fortunate to have been born in the greatest country in the history of humankind and to be driving a Ford pickup?" Have a Blessed Christmas everyone.

 

To everyone posting on here....its a VERY COMMON problem...and everyone of them that i've seen, heard about, or talked to anyone about it solved it with an alternator....the truck will still run fine...the alternator will probably last you 100,000 miles or more without ever replacing it....but seriously...if it annoys you that much....go have it replaced or rebuilt with ALL new parts....take it from those of us who had our trucks in 10 times, overnight, in bitter cold weather to get to this diagnosis....ITS YOUR ALTERNATOR

 

amen. New alternator cured mine after many belt lubes, belt change and other f'ing around.

 

I was going to create a new post but saw this one on the very same issue I have started having. I have had my s cab 5.4 since new and have never heard any whistling,squeling or anything like that until last weekend I installed a new Roush Billet style grill. First ride after the install as soon as I got to 60mph I had this whistle kind of like a coaches whistle let off the gas goes away get back to speed comes back same exact situation at 70mph. I think it's the gap between the grill surround and the hood. With the Roush I noticed a bit of a gap versus my stock which was totaly flush. Wind passing over that gap could certainly cause the whistle, I think that is why some people can not duplicate it standing still at the same rpm etc... I just think it would be a bit to coincindental for anything else to be the culprit. I plan on trying to put something in the gap to see if it's that or not. It could be possible for some stock surrounds to have a gap as well.
thanks

 

My 2005 5.4L does it in park as well as when under way but only when it is below 30F. Usually it is triggered by subtle changes in engine RPM. AND...I have had an aftermarket grille insert since I bought the truck in April '08 and it was quiet until just recently when the temp took a dive. I'm calling the dealer to have it looked at.

 

TSB-08-4-2
Cold Start Fead Hoot-Whistle Noise-built before 1/c
Pub. Date Feb 7, 2008
F150
5.4 and 4.6 engines built before 1/28/08 may exhibit a front related high pitched metallic whilstle/hoot noise after a cold soak 4.4 C. Noise may be caused by the grooved nylon FEAD idler plly.

Service procedure to correct. Replace the nylon FEAD idler pully 6L3Z-6C348-A Idler Pully.

I have this problem this winter in Michigan on very cold days, 10 degrees F and colder. I hear it at about 40-45 mph, and 65-70 mph. I thought my alternator was going to blow up. I have not got it fixed yet, now its in the 20s and does not make the nose. But NOW I know the problem.