Great thread! I have been looking for a solution to this problem for awhile now.
This is what my truck sounds like....this was on the coldest day this year. There is some static noise from my camera not the truck.

http://www.youtube.com/watch?v=U8weYqPtuQg

that is what mine sounded like, and a new alternator fixed it!

that whine brings back painful memories. im gonna have nightmares now. i never wanted to hear that damn noise again.

Sorry!! Just wanted to make sure my noise was the same as the others. Does anyone know if it the bearings or the windings in the alternator that make that noise?

Yep thats exactly how my 04 5.4 sounds on cold mornings! It only does it for the first mile or two then its gone.

I put one of those stupid throttle body spacers in and now my throttle activated whistle is pretty much gone but I do have a whoooooshhh sound sometimes. I think its just resonance from the K & N.

This sound is a lot easier to live with than the whistle sound so If any of you have a throttle activated whistle, try a throttle body spacer. I used the AFE unit. $100 shipped.

Exact sound i'm getting as well!

Yep, same sound I get when it's really cold. Very intermittent, and goes away fairly quickly. Absolutely not a bother at all.

My engine whine is completely different, absolutely atrocious, and never ending while giving the engine gas at any speed. Foot off gas, engine whine completely dissappears. Insane.

yup, thats that annoying sound, although mine doesn't go away when its warmed up

Add me to the list. Driving me bonkers.

Same here
 

I've noticed the same thing - MPG dropping. Had the truck 4 winters and this is the first time it's happened. Anyone else seeing the same thing? Shouldn't MPG go UP a little since the cold air is denser?

This is my third winter and the mileage goes down everytime. I think they add more ethynol in winter gas.

I get the whistle when it's cold as well. I adjust the throttle as soon as I hear it kicking in. Once the truck is well warmed up it tends to disappear for good.

Thanks for the compliment. Yeah, I trade every year just because I rack up mileage pretty quick and the dealer I work with gives me pretty good numbers. We've been a little slow with work this year, so I have been a little low on the mileage side - only about 4,000 miles a month so far. At this rate, I'll barely reach 50,000 by June, which is about the time I'd normally be ready to move on. We'll see how things progress. I'd really love a 2009. I'm already scheming, but used values are in the tank, and I doubt the boss wants to give this one away. I'm sure you'll see some posts in the next several months before I pull the trigger. ;)

The reason for MPG drop is simple.....you are right colder air is more dense(hence the reasoning for cold air intake kits). To account for the denser air the computer must add more fuel to maintain the proper air/fuel ratio. If it is really cold then the computer must add alot of fuel....decreasing MPG and MPT(miles per tank)....but the nice part is that youll gain some HP

I have the same noise....tons of guys do.
Theres got to be a solution.

Gentlemen, Head to your dealerships with this TSB!
http://2005stang.com/gallery/albums/...oot_wistle.pdf

Posted in this thread today by fitz888 ----->THANKS fitz!!! :banana::rocker::wave::beers: :thumbsup:

https://www.f150online.com/forums/20...ot-whisle.html