I’ve got a 2020 F350 platinum I’m having issues with. It’s got a whistle when you let off the gas pedal going over 40 mph... sound stays on till about 35mph then goes away. Local dealer has no idea... help me out!

 

Welcome to the site..

What engine?

 

6.7 with the 10 speed trans

 

I don't see any Service Messages for that specific concern/noise.
It almost sounds like a vacuum leak/bleed, since it falls off at lower engine speeds/RPM. But being diesel, they don't have significant engine generated vacuum.
Does it sound like it comes from the engine bay, not the instrument panel area?
Can you duplicate the noise on a throttle snap, stationary? Or, does it take a slight delay to develop/appear on a deceleration in motion?
Can you record the sound and post it here?

 

I can’t make it make the sound stationary, there is definitely a pause for the turbo psi to dump and rpm to go down before the noise starts. Sounds will continue with rpms 1800 and down. Sound kind of flutters but there’s a spot in the gas pedal if you lightly hold it, so you’re still decelerating, that will keep the noise constant. Posting the video sorry for the late reply, haven’t driven in a few days.

 

sounds to me to come from the engine bay, sound is noticeable from outside with windows down. Won’t let me upload the video from my phone onto hear

its up on YouTube “2020 f350 platinum whistle”

 

Load it onto youtube (set up an account if you have to)

 

It’s up on youtube(thanks for the idea) under “”2020 f350 platinum whistle”
let me know if you can’t find it

 

 

Heard a lot of tire noise,, didn’t hear a whistle ?