2004 6.0 making loud hissing sound

[dossonline]

i have a 2004 diesel excursion making a loud hissing sound. I have checked all the boots and intercooler and found no leaks. The sound seems to be coming from the turbo. I replaced the electronic valve on the turbo and it made no difference. Any help will be appreciated.

Dossonline@bellsouth.net

[Raul@Stealth Automotive]

is it a stock truck? and is it more like a whistle or hissing sound? does it make it at idle?

[dossonline]

bone stock. it is a hissing sound, it makes it at idle or under acceleration, you can hear it louder at the drivers door than at the front of the motor. If you unhook the modulator or whatever you call it it quits, if you hook it back up it starts again. I was told that modulator regulates the boost and when it is unhooked the truck makes no boost and that is why the noise quits. My problem is i don't know where the sound is actually coming from, so i don't know what to fix or replace

[2005F250]

The sound is the turbo.

[hager5739]

Hissing sounds liek an exhaust leak. I would check for cracks around the flange where the downpipe and turbo are connected. I would also look and see if your waste gate is sticking.

[Raul@Stealth Automotive]

Originally Posted by 2005F250

The sound is the turbo.

i think i have to agree... its prob just the turbo whistle... youll hear it a lot more if you put a aftermarket intake and chip

[Performance Oil Products]

could be a CAC boot. Take a good visual of your entire turbo system. If not could be stuck nanes in the turbo

[dossonline]

this noise just started and now the truck has no power. Someone else i spoke to mentioned stuck veins on the turbo, but would it still make boost with stuck veins? the noise is for sure air from the turbo, is there a relief valve or anything of that sort on the turbo that could be stuck open? The noise happens at idle and increases with throttle

[Raul@Stealth Automotive]

Originally Posted by dossonline

this noise just started and now the truck has no power. Someone else i spoke to mentioned stuck veins on the turbo, but would it still make boost with stuck veins? the noise is for sure air from the turbo, is there a relief valve or anything of that sort on the turbo that could be stuck open? The noise happens at idle and increases with throttle

could be a bad waste gate....

[dossonline]

i am a lot more familar with the cummins and the 7.3 powerstroke(maybe a bad word on here?) I just recently bought this excursion with the 6.0, so can anyone provide a diagram of the turbo or tell me where to find the wastegate? I would assume it is on the back side of the turbo, but not exactly sure how to get to it or how to tell if it is stuck or operational? Thanks for the help