Last year it drove me nuts that I could not figure out what was whistling on my truck. Only happens in the winter when its cold. And only happens at certain RPM's-around 1800-2000rpms. Throttle partially down

Any ideas?

 

There was another thread in this forum that had a few guys saying they've had issues with idler pulley's, belts, etc.. I have an issue with the Power Steering pump making an aweful whine/growl after its been sitting in sub-15 degree temps overnight, but it clears up within a few seconds.

Does it sound like a belt squeek, or a mechanical noise?

 

Mine just did it this a.m. after a soak all night at about 17 degrees. Sounds more like a kazoo to me. As annoying as it is it seems to be harmless. All three of my last F-150's have done it ('04 '06 and now my '08).

 

7 degrees here in NW Indiana and my power steering pump I swear is the culprit of a slight whine/whistle. The only reason I suspect this is because my steering fluid is no doubt thicker due to the cold and taxing the pump greatly. Turning the truck in either direction is more like having power assist than true power steering (used to have this on my '69 Mustang til I went w/ a rack and pinion setup and ditched the steering box and power steering pump assist). This is on an '07 FX4 Screw btw.

 

Its definitely not mechanical. Is literally sounds like someone is whistling under the hood. Almost like a vacuum leak. But only when its cold...
What is "activated" under load when its so cold out? Kinda like a choke on a carb motor.

 

I hadthe problem on my 08 the first winter. Seemed like clockwork it would make the tea-kettle whistle once it got down below freezing on a cold engine. I took it in under warranty, they changed the idler pulley out and the noise has been gone ever since.

 

Here is the thread https://www.f150online.com/forums/20...ngs-video.html Apparently there is a TSB for it.

 

Alternator. There is a thread somewhere around here with a ton of posts about this.

 

yea mine does that to on cold mornings, I just figure it has something to do with the cold air being sucked into the engine instead of the warm air.

 

See, mine is different. Mine happens WHILE DRIVING not at start up. I swear it sounds like a vacuum leak but only under load and cruising 65-70 mph and 1800-2000rpm.

 

try turning the A/C off, mines does it and when i turn the A/C completely off it goes away

 

from what i've read its the alternator

 

Heres a video. Sorry for the bad quality it was with my Blackberry

http://www.youtube.com/watch?v=YPPslF0bV4I

 

mine does the exact thing and its so embarassing it makes me want to cower down. I hate winter for this reason. I get made fun of enough for being a Ford guy and stupid stuff like this only adds to it.

 

Mine is the exact same as yours, I think I might call the dealer today and see if the have a idler pulley on the shelf.