Add me to the list. My sounds is a cross between someone sucking air through a straw and a whirl from a turbo. Ah if there was only a turbo under the hood :mad:

Just want to pass on the message that I didn't get a single squeal all winter long (once I had the new alternator installed).

i'm surprised know one has mentioned the TRANSMISSION. my 04' 4.6 does it, i've been in an 06' 5.4 that does it and another that did it. mine will do it even after 30 min of driving in the winter. when i change the load/throttle position, it goes away. i really think its the tranny, i can hear it under the floor.

I promise you it isn't, unless you're hearing a different whistle. If you're in cold weather you'll know what this is as it is not a constant noise. Ford has a TSB out on these bad alternators and has been replacing them as I confirmed with my dealer two years ago.

i'm bringing this back...


duke, if you're still around, did your noise go away after the truck warmed up??

mine 04 5.4 is whistling at 35 , 60 and 70 mph all the time since its been below ~40-50deg. it definitely is a whistle and not a whine. i can duplicate the sound exactly with out the truck.

the only thing i can add to this thread is in cold weather most of the time the engine compartment will be damp especially if driving in snow that has salt on it and is melting, you park your truck for the night, come out the next morning, there will be some type of frozen/ watery residue under the hood and the motor will squel under these conditions, usually for the first 30 seconds or so. if it happens periodically while driving after you have been on the road for a while then i dont know. i only read the first page of this thread because it was from 2006.

I used to have a bit of a whistle, but after installing my Gatorback belt, it seems to be gone.

Its not the MPH, its the RPM you are at. Look at your tach at these speeds and I bet you will be around 1800 or 1900. My truck does the same thing, the colder it gets the louder the noise.

Okay, I may have not had the same issue but it sounds like the same. I have an 08 F150 5.4. I would have a sound that was a mix of loud squeeling and a sucking air squeel sound only the first 5-10 minutes on a cold morning. I called my dealer and they said that I would have to leave it over night. I asked them if I brought it in now could they at least check it out (it was driving me crazy and pissing me off). I did and they checked it out and found that there is a service call on an idler pulley. He said that the plastic it is made of is not to standard. They did not have the part, but had it the next day. I dropped my truck off and they replaced the pulley. I have not had the noise since they replaced they idler pulley. I hope this solves everyones problem.......

Its definatly throttle related, the slightest movement in the fuel pedal the whistle will get louder or softer. Mines LOUD, i've passed people doing 50-60 and they look at me like what the heck was that....

Mine has nothing to do with temperature whatsoever. Nor does it only make the sound only at startup and then go away after a little bit.

My vehicle sounds totally normal until I step on the gas. As soon as I am giving it gas, the engine begins to howl. It will do this whether I am going 1mph down my street, or 40mph down a road, or 75 mph down the freeway.

The noise will go away almost immediately after I let off the gas pedal. It returns immediately after I step back on the gas pedal. Any temp, any speed.

It only makes the howl while giving it gas. No gas, nice and quiet running. Any amount of pressure on gas pedal, howling begins and continues uninterrupted until I remove foot from pedal.

My truck can be rolling at high speed after getting going and not make any sound at all, so it's not the tires or anything like that. For example, I can get up to 45 and let off the gas and coast. While coasting, my truck is nice and quiet even though it's still going 40+. Whatever the speed, doesn't matter. Nice and quiet... until I step on the gas pedal again.

It's an absolutely awful high pitched howl that never ceases while I'm providing pressure to the gas pedal/gas to the engine. Even with the radio cranked it is still extremely prevalent and irritating and hard to hear over. Soon as I take my foot off the gas pedal, nice and quiet even if I'm still rolling at 90mph.

Something catastrophic is happening while I give gas to the engine. It's been doing this for years now and is the most annoying thing I can possibly imagine. Can't tell you how many headaches have occured from this, due to combination of noise and absolute frustration over this unholy breakdown in mechanical functionality in my truck. It's driving me insane, insane enough to think of purchasing a 2010 model even though I have no interest in a new F-150 until they actually fully remodel it.

One of my idler pulley's bearing's went out and that sound is nothing like this. The pulley is more of a ringing noise.

Yeh, I know the sound that you are talking about. I would have never guessed that my sound was an idler pully. It did not sound anything like a bad berring. I am just putting this out there because it sound very similar (some cases just progressed). Mine did go away after a while, but my truck only had 1000 miles at the time too. It also will cost you nothing to have Ford replace the pulley. If anyone is interested I can get you the part number that they replaced. Just thought it might help some of you F150 lovin brothers out there. I would hate to hear that you are driving a new Chevy or Dodge because of this noise...........

My squeal didn't start until i installed my airaid intake. I only hear it till the truck warms up and then it's gone. If I let the truck warm up while i clear off snow or ice by the time i pull out i won't hear it at all. Mine is 04 XLT 5.4 4X4.

I have the same whistle at cold start up.
I am in the same situation where I can not leave my truck overnight right now as I need 4WD every day.
I stopped in at my dealer today (60 miles away), and explained the problem. He pulled up a TSB about it, and made an appointment to have the idler pulley changed out. According to the TSB, it only affects '08's built before 12/8/08.

I must say my dealer service dept was very accommodating doing it this way - I can go to my appointment in a week and wait to have it changed out - it will be nice to be rid of that whistle!