strange whistle

[cornish2101]

i am having this strange whistle while driving steady at 60ish but doesnt happen all the time i have my exaust cut off and i can hear my turbo whistle but this is a different kind of whistle it's much deeper and im jus wondering if that is goin to force me to buy a new turbo soon if anyone has this problem (if it is a problem) or if anyone knows what this is

[vitalidle]

Is it a whistle or a hissing sound. When you hear the sound do you have any other issues with the truck such as loss of power?

[mschn99]

could it be turbo surge your hearing...is it kind of a fluttering sound??

[alberta 7.3]

may be an issue with the EBPV sticking closed

[bigcountrysg]

What about door Seals, or window seals. If they are not sealing correctly you can get a whistle too.

[NCHornet]

These things can be hard to track down. If it only happens while it is cold and stops after engine comes up to temp it is your EBPV and we will start to see a lot of posting asking what that sound is when it gets cold out.
If it is constant, check your filter minder, I had a high pitched whistle and when I popped my hood I noticed the entire bottom the that plastic filter minder was blown completely off!!! New filter minder and everything is back tomorrow.
If it only happens at highway speeds it is probably air or driveline related. I have heard a carrier bearing sound like a dull whistle inside the cab.
Good Luck

[cornish2101]

ok it's not the air filter or intake cus it was doin it 2 weeks ago and then i got my afe stage 2 and it still does it. it dont do it all the time only at 60ish stady no loss of power that i know about but when i gibe it gas it goes away and it has done it right after start up and like 30 mins after running all warm it doesnt do it all the time mabey like once a week im sure u all know what the turbo whistle is right ok well i have that all the time and this whistle is much deeper like goin threw a long cardboard tube and its now a window or door

[vitalidle]

Im willing to bet your exhaust back pressure valve is sticking a bit.

[lords88]

Yep sounds like the exhaust back pressure valve is sticking. I had a 94 powerstroke and it stuck all the time, it sounded like a really loud jet because it was straight piped. I didn't have anything for power but when it opened it would run just fine. It seemed to do it the most when it was cold and as soon as it warmed up it would be just fine.

[cornish2101]

and how do i fix that if thats what it is