ddc

I to have the annoying whistle in my 05 F150 w/5.4 liter. Minnesota winters are close to the coldest around. Mine has done it since it rolled off the lot with 3 miles on it. Bought it in Jan of 06, the dealer looked right away and said also it was the alternator, more belt slip they thought though. It only last a few seconds or so and will come and go at freeway speeds when very cold. -5 or colder. I have 27k on it now and the noise hasn't changed, I would think if it were a belt the noise would change as the belt wore, it hasn't. So, I would lean to the alternator. The intake gaskets leaking wouldn't that be picked up by the computer for a lean condition? Just a thought. I hate noises, this one hasn't bothered me yet, but it will if I start replacing the belt, idlers etc. and can't nail it down when the day comes.

rbailey3711

Hopefully someone will figure out this whistling noise. I have an '05 SuperCrew 5.4L, 54K miles; whistle just started this winter. Oh, have owned it since 2 miles on odometer.

brub27

The 04-08 4.6's are 2v but the 5.4's are 3v

stnygrm

i have the same problem, whistles under load when below 10 degrees
i changed the air filter thinking it was plugged but to no avail
please let me know if you find a solution

rbailey3711

I've been away for awhile; temperature, outside, is now in the 40's .... no whistling noises anymore. I was in the UP of Michigan last week and it didn't do it with the temps around zero..... Still wondering what the noise is from.

loganberry

mine has done it since day 1, it sounds like the alt belt to me.. the manufacturer said they couldnt find the problem and there for couldnt fix it, it anything its just annoying and not really a big problem....also i live in california, no hard winters here

bengardner1

I have a 2006 F150 supercrew 4.6L with the same problem, It seems like it is only at certain throttle positions and when it starts making the noise if i either let up on the throttle or accelerate just a bit it goes away, also i have had the truck for about a year and it seems like it is getting horrible fuel mileage now , it went from getting 600km to a tank to about 480-500km, i don't drive it any different
Ben

ddc

I'm back after a year and 10k more miles on the truck. Yep it still whistles just like it did.Pretty much the same as everyone describes. I was at a buddies shop a month ago and he the intake off a 05 f150. Had a miss, found a leaky intake gasket. He said"Its the webbing inside the intake that creates the noise we hear, why some do and some don't, who knows". The webbing is there, you would think the engineers that design these parts would want smooth surfaces for even flow. Also noticed there is a second set of butterflies for each cylinder, he said that was so when the motor is cold we don't floor it and wreck stuff. Maybe he was kidding. While I was standing there he was also removing spark plugs, thats a job that ford better figure out or there is gong to be some really pissed off people in the future. If don't know, don't attempt replacing plugs unless you HAVE TO REPLACE THEM!!! Another one of those"Don't touch it unless its absolutely broke. Good luck.

j air

My 06 used to make a ringing whistling sound that would come and go, especially in the cold, it was an idler in the serpentine belt. The left side as seated in the truck. It sounded like an air leak and would come and go with RPM changes. Listened to it for 2 winters before I could figure it out. Take the idlers off and see if it is a dry bearing. Good luck

ddc

I, still have this whistle as I described 4 years ago. Now have 74k on the beast, and the whistles starts at about 30 degrees outside temp now days. But its no big deal, just annoying. I have replaced all the idlers, and ready to replace one again! Replaced OEM belt and the tensioner pulley last month. I did spin all the idlers and the alt, the alt sounds real dry, so I'm going to ask about bearings for it when I hit NAPA again. Now, I started the motor cold with the belt off, and I still have a squeal coming from the intake area, another thread on that if anyone is interested!!!