My 2005 SCREW 4.6 Stock. Is doing the same thing. I am hesitant to start throwing parts at it. Hopefully someone can figure this out. I tried carb. clean it didn't work.

 

I have a 4.6 and the little whistling noise you hear coming out of the intake area is normal...put an aftermaket intake/TB spacer and it's gonna be even louder!!!!I actually like it lol!!! I don't know exactly what cause the whistle but mines been doin it since I bought it brand new(stock) and I know for sure its not harmful for anything...I wouldn't even worry about it!!!

 

i have an 06 5.4 and i had the same prob i took it to the dealership and they ended up pinpointing it to the altenator so they replaced it and the whine is gone.....

 

Nahhh the noise I'm hearing come from the intakre area 100% sure of it!!!!I can play with the sound with the gas pedal!!!I could almost whistle at near by chicks lol!!!!Anyways back to the subject...I ain't sure Exactly what it is but if you have a 4.6 and it whistles a 1800-2000 rpm it's normal I mean my alternator couldn't of been bad when I bought it brand new(I hope anyways lol) but I had and 03 king ranch(5.4) and it never whistled like my 07 4.6 does!!!4.6 whistling...get used to it, its normal!

 

Actually one of my buds is a mechanic whos been working for ford quite a while, I'll try to figure out with him EXACTLY what's whistling in the 4.6 but 5.4 can't really help ya(check your alternators)!!!!!

 

Adkleaddog. Any luck!! I am also looking for a fix.

I have noticed the same thing on my 05 here in wisconsin. sits in a heated garage and as soon as I hit 68 -70 mph on the drive to work on a 15F or less morning something makes the noise. 71mph or 67 mph the noise is gone.

 

Just FYI if you have a 2007 or 2008

TSB 08-4-2

COLD START FEAD HOOT - WHISTLE NOISE / BUILT BEFORE 1/28/2008
Publication Date: February 7, 2008

FORD: 2007-2008 Mustang, Expedition, Explorer Sport Trac, Explorer, F-150, F-150
LINCOLN: 2007-2008 Mark LT, Navigator
MERCURY: 2007-2008 Mountaineer


ISSUE:
Some 2007-2008 F-150, Mustang vehicles equipped with a 4.6L and 5.4L engine; 2007-2008 Mark LT, Expedition, Navigator vehicles equipped with a 5.4L engine; Explorer, Mountaineer, Explorer Sport Trac vehicles with 4.6L engine and built before 1/28/08, may exhibit a front end accessory drive (FEAD) related high-pitched metallic whistle/hoot noise after a cold soak in ambient temperatures below 40 °F (4.4 °C). This noise may be caused by the grooved nylon FEAD idler pulley.

ACTION:
Follow the Service Procedure steps to correct the condition.

SERVICE PROCEDURE

NOTE: FEAD IDLER PULLEY NOISE MAY BE MOST APPARENT AT OR NEAR COLD ENGINE IDLE SPEEDS (APPROXIMATELY 1200 RPM). NOISE DURATION IS LESS THAN 10 MINUTES AFTER STARTUP AND WILL BE ELIMINATED WITH FEAD BELT REMOVED.



Replace the nylon FEAD idler pulley, refer to Workshop Manual, Section 303-05.

PART NUMBER PART NAME
6L3Z-6C348-A Idler Pulley


WARRANTY STATUS:
Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.

OPERATION DESCRIPTION TIME
080402A 2007-2008 Mustang 4.6L: Replace FEAD Idler Pulley Includes Time To Remove And Install Serpentine Belt (Do Not Use With 8678A, 8620F) 0.3 Hr.
080402A 2007-2008 F-150/Mark LT 4.6L/5.4L: Replace FEAD Idler Pulley Includes Time To Remove And Install Serpentine Belt (Do Not Use With 8678A, 8620F) 0.3 Hr.
080402A 2007-2008 Expedition/Navigator: Replace FEAD Idler Pulley Includes Time To Remove And Install Serpentine Belt (Do Not Use With 8678A, 8620F) 0.4 Hr.
080402A 2007-2008 Explorer/Mountaineer/ Sport Trac 4.6L: Replace FEAD Idler Pulley Includes Time To Remove And Install Serpentine Belt (Do Not Use With 8678A, 8620F) 0.4 Hr.