New alt on my 05 and problem solved. Whistle free!!

Whistle
 

See if it goes away when you shut of the heat.Use the air control ( for windshield and so-forth) and see if it stops. If so they make an anti-whistle that goes in the heater hose.

Tone Sound
 

Guys,

Today was my first day out on the highway for longer than just a few minutes with my "new to me" 2005 Lariat 5.4.

I have a squeel that seems slightly different from all your descriptions: it sounds like the high pitch tone that sounds just like when the TV feed ends late at night and you have the color bars. It's cold this morning (-10F) and it seems to happen when the truck is warm and at any speed after 55 mph. I took it up to 70-75 and nothing changed, not the pitch, not the volume, nothing. I slowed down and it went away below 55 again.

It's tough to tell where it's coming from, like it's coming from everywhere. Thought maybe it was the audio system so I turned the power off the (aftermarket) head unit and the sound didn't go away.

Any ideas? I was pulling my hair out after only a few minutes! Thanks.

,Marc

*Bump*

Anyone?

It's probably an idler pulley bearing. You could remove your belt, run the engine and see if you can hear it. If it goes away, it's one of the idler pulleys or a bearing on one of the driven accessories. Spinning them by hand with the belt off might help you locate it.

I'll have to give that a try. However, would an idler pulley bearing sound (pitch, volume, or other) not change with engine speed? This also only happened in OD at 55+ mph, and not at the same engine rpm's in any of the other gears... Like I said I only took it up to around 70 or 75 mph to see if it would eventually go away but the whistle remained completely constant in every way between those speeds, then it would completely go away again down around 55 and slower (not gradual, it would just disappear).

If it happens on the way home again today I'm going to try absolutely everything this time to see if I can narrow it down some more, including playing with the HVAC...

It should change with engine rpm. If you only hear it in OD, it might be a transmission issue. Try locking it out of overdrive and see if you can still hear it.

Idler pulley bearings would be a bit obvious with the hood open, but could start at a higher rpm. Almost always they are nosiest when cold.

Just had my idler pulley replaced last week... squeaked like an sob esp when wet

Judging by the number of pages I am not alone. I have a 2005 XLT Supercrew, and I have both sounds.

A "whooting" noise at cold start up, that goes away after a few seconds/minutes. I successfully ignored it for a couple years, but now it has started to continue (albeit quieter) after warm-up, sounds like a power steering pump run dry.

I also have the very high pitched whistle...I notice it intermittently at highway speeds and especially as it gets colder. When I first heard it I was convinced it was feedback in the stereo, but it continues with the stereo off.

I am at 170k on the truck, so I am going to start with a new belt and tensioner pulley. If that doesn't work I guess an alternator is next. I am posting so I can report back with results.

Although I am liking the look of the 2011's.

Long story short, one idler pulley and a new belt, all noises are completely gone

Yup I figured that was it... I squeals like crazy

Yeah I had similar issues and replaced 2 idler pulleys and put on a new belt. If you have a squeelin noise always check your idlers. Try spinning them. They should stop spinning real quick. If it keeps spinning with no resistance more likely need to be replaced.

mine does the same thing but if u hit the gas harder or let of itll fade and go away until youre at a constant pedal position usually just low cruising speed

Its not a squeal its more of a whistle, and mine only does it when its below 30 or so aswell. Funny if you step on the throttle harder or let off it goes away?

Haven't heard anyone here mention Vaccum leak. thats what it is. Something is conracting in the cold, expanding in the heat.
WHen it whistles in the cold, take a hair dryer under the hood and follow vac. lines, and across the intake. if it goes away, guess what.