My husband just bought an F 250 4x4 7.3 liter diesel. He got a good deal or at least we think he did. When he cranks the truck it makes this noise that almost sounds like a dragon breathing. .. neither of us have ever heard a truck do this before. Is this common & what causes it? Is it safe to drive? I'm sorry I don't have much more information the previous owner was not very forth coming. I've attached a video of his truck to better convey the problem
There is no one sitting in the truck and no buttons, pedals, levers or switches being touched.He only cranked the truck and stepped aside. Stops as soon as the truck is "warmed up" (about 1 min 30 sec total)
Diesel truck: http://youtu.be/gaKI_hohWmM

 

The video isn't working for me but what your hearing I believe is the ebpv (exhaust back pressure valve). They come on when the truck is cold but should shut off as soon as u touch the breaks. It poses no threat unless it is stuck closed. Which does happen some times. Let me know if you have any more questions.

 

https://www.youtube.com/watch?v=gaKI...ature=youtu.be

 

Ok just watched the vid. That's definitely not a typical noise. Do the rpms go up and down or is it just the noise? It almost sounds like the EBPV could be opening and closing but I'm not sure why it would do that.

 

thank you for taking the time to respond and it sounds like it might very well be my problem because it only does it the first time you crank the truck each day and were told the sound is worse over the winter. I've changed the privacy settings of the video so maybe now you'll be able to view it but you might have to copy and paste the link in to YouTube
Diesel truck: http://youtu.be/gaKI_hohWmM

 

I'm not sure if the RPMs go up or not I will look first thing in the morning when he cranks the truck

 

Ok let us know. I'm pretty sure its an ebpv issue and you shouldn't worry about it much but you could always do what I did and delete it.

 

The RPMS do not go up & down its only the noise

How do I "delete it "

 

There is tons of info about deleting it on the internet. Just look up 7.3 power stroke ebpv delete. You can buy the parts or modify what's on it.