Wierd noise! What the heck is it? Help!

[res0wc18]

so i have this noise that sounds like and off turbo sound coming through the
exhaust making a shhhhh sucking type sound that is louder than ****. it sounds like one of those diesel burning forced air heaters! the sound is there even when the truck gets hot. Ive eliminated fuel gelling etc. The turbo is getting clean full pressure oil etc. So i have narrowed it down to something electronic because when i shut the key all the way off after experiencing the sound and start it right back up the sound goes away? When driving the truck with the sound the truck seems to be losing boost because when i get into the power it takes a second or two and the sound goes slightly away but returns as soon as the hard throttle is evened out.

could it have something to do with my glow plugs being shot?

What the heck is it? I have done the following things

1. fresh oil and filters.
2. fresh fuel filters with plenty of anti gel etc
3. i cant notice anything leaking or loose?

 

[NJKen]

Sounds to me like you are describing the exhuast backpressure valve operation to a T. It is normal if the temperature is cold and the ECM may do it even if the engine is warmed up. If it really bothers you do a search on EBV belete.
Ken

 

[res0wc18]

they have exhaust back pressure valves on the 97's? i thought that was 99 and newer? So its suppose to do this. Does it make it warm up faster or whats the point for it to do this?

it doesn't hurt it at all to do this? so would the truck looses power from this and when it was cold have the rpms drop way down when you step on the gas?

 

[1dieselman]

The EBPV is on all the powerstrokes since 94. You may want to do a scan to find out if it is malfunctioning. Once the truck is good and warm it shouldn't come back on unless you leave it idling for a long period of time in below freezing conditions. Yes it is there to help with faster warm ups.

 

[Mike]

Yup, its the EBPV. Its to aid in cold warm ups, the valve shouldnt be closing once you are warmed up, but you described it perfectly. Loss of power, drop in RPMs and a SHHHHHH noise.

 

[res0wc18]

ok so where is it located and how hard is it to replace? Cost of part?

 

[Mike]

Its located right in the turbo outlet, there is most likely nothing wrong with the EBPV itself, it is just closing at the wrong time. You can clean the EBS tube which runs off the bottom of the passenger side exh manf and up to the sensor located front top center of the engine. It gets plugged with soot sometimes, or possibly the EBS itself is bad but not likely either.

 

[1dieselman]

It is located in the exhaust outlet of the turbo, a real pita to get to, its easier to pull the turbo, what most guys will do is remove the valve and weld the hole that the shaft goes through shut. Don't know what a replacement costs.

 

[res0wc18]

"You can clean the EBS tube which runs off the bottom of the passenger side exh manf and up to the sensor located front top center of the engine. It gets plugged with soot sometimes, or possibly the EBS itself is bad but not likely either"

What the heck is that the actual sensor. Got any pictures?

How would i clean this?

 

[Mike]

The EBS is circled in red. You clean the tube by taking it off the truck and running a stiff cable through it, works good to chuck it up in a drill and as you feed the cable in the tube spray it with carb cleaner.

 

[94f450sd]

just unplug the black 2 wire connector on the compressor side under the intake boot and never deal with it again.

 

[res0wc18]

that wont trip something or cause horrible losses in power fuel mileage etc

 

[94f450sd]

nope itll set a code cuz it aint working but no check engine light,no loss in power or fuel mileage.

 

[rthomas]

somewhere around here theirs a wiring diagram on how to turn the ebpv into a exhaust brake and make the function of it manual, last year mine did the same thing and i just unplugged it with no ill affects

 

[towcat]

here's pics of a recent teardown.
pics 1 & 2 is the valve in the closed and open position.
pic 3 is the turbo pedestal the the ebpv solenoid connector in the front and the hydraulic actuator rod for the valve sticking out the side.