2004 F150 strange whine/whistle at certain speeds?

[renegade_987]

Hey guys, hopefully y'all can help me out. My F150 for about 2 months has had a strange noise while driving, like a mid to high pitch whistle or whine, almost like a turbo diesel whistle but a different pitch. This evening a friend and I narrowed down the noise to occuring between 17-20 MPH and 25-30 MPH (more prevalent here) Outside of that we didn't notice it at any other speeds. Any ideas what this could be, Im stumped? Thanks!

 

[CHARLIEBRONSON21]

Possible wheel bearing?

 

[gregk24]

If its RPM dependent it could be a plugged up PCV valve.

 

[renegade_987]

Originally Posted By: gregk24
If its RPM dependent it could be a plugged up PCV valve.


I'd say its fairly RPM dependent since its always around the same speeds.

 

[gregk24]

Originally Posted By: renegade_987
Originally Posted By: gregk24
If its RPM dependent it could be a plugged up PCV valve.


I'd say its fairly RPM dependent since its always around the same speeds.


The PCV valve would be a possibility, our Uplanders makes a whistling/whining sound when accelerating around 2500 rpm or so.

 

[lugNutz]

Front or rear? Does it do it if you let off the gas?

 

[Brybo86]

I'm.assuming this is an automatic, does the sound happen if the transmission is intentionally kept in a lower gear, try it and see what you hear

 

[MNgopher]

Only happen when very cold outside? On my 2004 F150, it was my alternator. Replaced it and never had the sound reappear. Was pretty common on F5150's of that vintage here in very cold weather (as in below zero generally).

 

[Rand]

what engine? what rpm is the engine at? does it vary with rpm or speed?

last question.

does it sound like a pregnant whale moaning?

 

[01rangerxl]

Does it happen when you get on the gas, or is it unrelated to throttle position?

My Ranger did this at lower speeds when I would give it gas when the pre-cats were melting/clogging up. It was down on power too, and would detonate/misfire above 3000 RPM. It just couldn't move the exhaust, and I guess the abnormal exhaust flow was causing the noise. Replaced the y-pipe assembly and all symptoms, including the turbo-like whistle, went away immediately. It never did set a catalyst efficiency code. Not saying you should throw a y-pipe at it, but it's something to investigate.

 

[SOHCman]

Isnt an 04 f150 subject to the TSB for using 75w-140 indtead of 75w-90in the diff to quiet gear whine?

What oil are you running in the rear differential?

 

[SOHCman]

Yup, TSB 05-23-3
1997-2005 f150 need to change to a 140 gear oil.

 

[ondarvr]

I bought an 03 F150 at a very good price because it had very high pitched whistle at certain speeds.

I drove down the road on the second day and found it was the plastic frame on the drivers mirror, it had come apart slightly. I squeezed it and it popped back together, stopping the whistle instantly.

 

[SZR48207]

Did you recently put on new windshield wipers? The Bosch brand wipers on my F150 would whistle at higher speeds due to the metal frame design.

An easy way to check: Reproduce the whistle while driving and then turn on the wipers. If it goes away once the wipers move, you've found your culprit.

 

[artificialist]

My grandfather had a 1990 Chevy Silverado with a similar problem. It was explained that wires connected to the stereo weren't shielded well enough. When the stereo was off, the noise went way. The pitch would change when the RPM changed.

Was the stereo on or off?

 

[Garak]

Originally Posted By: Reddy45
Did you recently put on new windshield wipers?

When I had my Lightning (and my LTD before it), a tiny bit of ice buildup on the antenna would whistle like crazy. No ice, no noise; a lot of ice, no noise. A bit of ice, look out.

 

[KitaCam]

Physical...wind through a part as suggested...perhaps a bit of loose chrome...look around, feel around, tap around them...
Mechanical...bearings...in any number of rotating engine/body parts...try disengaging a belt or other part one at a time...
In either case, it's a sleuthing process...often solved by happenstance and luck just as it started...