DRobison

My 2004 makes the high pitch noise when it is cold. It is speed or RPM related and I am about 98% certain it is under the dashboard.

It is definitely not weather seals or wind noise.

loon

was also told that if i took apart the dash and tightend all fittings there was no gaurantee that it would cure the problem......

vinster

I have 05 5.4L, it has a whisle too. It does it when cool out. I think it has a vacuum leak. I had a car that was doing the same

dra12901

My dad just recently bought a 2005 F150 that has this same whistling noise. While I haven't yet figured out exactly where the noise is coming from, I have a pretty good idea that the noise is coming from a leaky vacuum "motor" somewhere under the dashboard. I had a car that developed a similar noise years ago.
I just today signed up for this forum, so I'm not too familiar with how it works. If anyone has any similar noises I'd appreciate it very much if they would let me know what it turned out to be and how they fixed it.
I plan to have a friend drive the truck while I try to get under the dashboard on the passenger side enough to try to find which general area the noise is coming from. From there an easy way to isolate the leaky vacuum motor is by clamping the vacuum hose to the various vacuum motors with a pair of hemostats (vise grips will also work) one at a time until the noise stops. (DON'T try this while you are driving!) This will shut off the vacuum to the vacuum motor that is connected to that hose, and hopefully tell you which vacuum motor(s) is(are) leaking. When the noise goes away, you found the leaky motor! Replacing these vacuum motors can sometimes be easy but depending on which one is bad and where it is, they can be an absolute nightmare too!!

dra12901

My dad just bought a 2005 F150 that has this same whistling noise coming from under the dashboard! If you find out what it is, please let me know! It's really annoying!!
Dan Anderson
Plattsburgh, NY

NicGB79

I am thinking my noise is coming from the engine compartment and not under the dash. One day it would only happen -1(F) or below. As soon as it was 0 or above it would stop. I happen to be driving through hilly terrain so the temperature fluctuated quite a bit and -1 was the magic temp.

Nic

outdoorsman1201

Dealer told me that the problem was cold air going through the plastic intake. Also told me that there was not a fix for it and it happens on about 40% of the trucks.

Makes me proud to own a ford!!

NicGB79

Nice..... The other 60% probably live in warm-weather states.

tmal2

Hi guys, I've got a 2005 F-150XLT with the 5.4 engine. I've got the same whistling/whining problem with my truck. This only happens when it's cold outside and at highway speeds. The noise sounds like it's coming from the front left wheel area but It's tough to say for sure since sounds travel so much.
If I go 60 MPH and the truck has not warmed up the noise starts. If I give it a little gas and bring the RPMs up 100 or so it goes away or if I drop the RPMs the noise goes away. It seems to happen most often in the 1800-1900 RPM range

Once the truck warms up (8-10 miles) the noise goes away.

I hate to pay the dealer to look at it for something that they can't fix. Has anyone had any luck fixing this problem?

ME_Engineer

To all who have experienced the annoying high pitch whistle in an F150 (Current vintage), I ran into this a few months ago and have resolved it for my truck. I though I'd pass along the details. I first noticed the whine/whistle as cold temps hit (typically below 20deg) and RPM was around 1700. At first, I thought it sounded like a pump or intake whistle, but after a few days at -15 degrees, I zeroed in on the alternator. I pulled the belt and could actually feel some binding in the alternator shaft (at extreme temps). I removed the alternator (a new one is $325!!!) and decided to attempt a "fix" of what seemed to me to be a clearance issue between the shaft/bearings/thrust plate. The shaft can be accessed by carefully removing the small cover on the back. I supported the alternator housing and tapped the shaft back and forth with a hammer to effectively shift things around and loosen it up. Once looser, I clamped the unit in a vice and spun it up with an air impact (thinking that might get things to settle in a more neutral location inside). Performing this routine a few times, it soon became much quieter and turned more freely. I reinstalled it and it has now run for about a month in a Maine winter with temps often reaching -20 degF. No more whistle! Just a thought of some place to look for anyone having the same issue. Looks to me like Ford's supplier of alternators needs to review their cold weather clearance stackups. ...Basic rookie engineering mistake. - Good Luck!