when the engine is cold or warm doesn't make a difference...and i'm between 40 and 50 mph does anyone else get a hissing noise...it sounds like the turbo is sucking in a lot of air but not doing much, but then all of a sudden it gets going. I normally encounter it when im accelerating from 40-50 to a highway speed...when im on it and accelerate through that range i don't get it. is it just between gears or is their a leak?

 

sounds like the ebv(exhaust backpressure valve) this aids in warm up sometimes it sticks on
i personally got tired of mine staying on all the time when driving so when i but the turbo on i got the highflow outlet and non-ebv pedistal

 

Did that blow your mind?.... sorry I had too...

On a more seriouse note I have noticed the same thing at times, no clue what it is but hopfully someone here will chime in soon.

EDIT: looks like some already did while I was posting

 

how would i go about doing that?

 

You don't need to do that. You need to find out what is going on. Pull the red line from the WG actuator and put it on one of the IC clamp bolts and see if it goes away. If not, unplug the connector to the EBPV solenoid and see if it goes away.

 

double post

 

pull the turbo off and the pedistal off and replace with aftermarket parts also u could gut the factory stuff do a search on gutting the ebv and there should be a write up on it
but since ur taking the turbo off i'd put a different one on since its already off
check out black widow diesel and dieselsite also u could check out hypermax
black widow diesel has the pedistal and high flow outlet

 

and if it goes away after unplugging...just leave it all unplugged?

 

Uhhhmm, if you want, but that will tell you where your problem is.

 

what would i have to do for each one to remedy the situation...i also have been hearing that people unplug the red line and leave it unplugged

 

Do one at a time and see what happens. No need to discuss what ifs.

 

If when you unplug the sensor it stops, then you could start by cleaning the tube and sensor. Follow this link to a great write up on that service procedure:

http://guzzle.rbmicro.com/ebps.html

Heres's a rundown on the basics of that system

Exhaust back pressure is controlled to provide more heat to the coolant for cab heating when ambient air temperature is below 7°C (45°F) and engine oil temperature is below 75°C (167°F) during low load. At high load, high speed conditions, the back pressure system is disabled.

The exhaust back pressure regulator solenoid and exhaust back pressure piston are contained in the turbocharger mounting pedestal. Turbocharger pressurized lube oil is routed to the exhaust back pressure solenoid. Oil regulated by the exhaust back pressure solenoid actuates the piston which operates the back pressure valve in the exhaust housing.

The Exhaust Back-Pressure sensor is a variable capacitor sensor that is supplied a 5-volt reference signal by the PCM and returns a linear analog voltage signal that indicates pressure. The Exhaust Back-Pressure sensor measures the pressure in the RH exhaust manifold. This sensor is used in conjunction with the exhaust back-pressure regulator to form a closed loop exhaust back-pressure control system.

An open or short in the Exhaust Back-Pressure sensor wiring will result in a low out of range voltage at the PCM, and the PCM will disable Exhaust Back-Pressure control.


Good luck and keep us posted,

Austin

 

when you unplug the red line and cap it off using the clamp bolt.it keeps the west gate closed..you will build boost faster and should be able to see around 30 lb of boost.. i think you are hearing the EBPV.. under the turbo just above the blue dot in this pic..is the plug for the EBPV..there is a wire locking clip on it..flip the clip back and pull the plug out..see if it still makes the hisssing sound...if it does..the EBPV is most likely stuck..if the sound stops..it could be the EBPS tube filled with soot and giving a bad reading..it will need to be cleaned out..

 

alright i unplugged the ebpv and the sound stopped, however i was not getting anywhere near my normal boost...i gunned it and it ran up to 10...the turbo felt sluggish with the ebpv unplugged.

i was on top of the engine and i noticed a lot of soot and a little bit of fluid in that catch bay...should i just clean the soot...i also checked the up pipe and there was no soot so i don't have an exhaust leak.

 

yes clean every thing out nice. are you sure its soot? look for where it could be coming from..if its oil..you will need to check the boots for loose clamps and split hoses ..did you un hook the red line???