EBPV Sticking
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Logistics Pro
Joined: Mar 2006
Posts: 3,678
Likes: 2
From: Rapid City SD
EBPV Sticking
What do you do for a sticking Exhaust Back Pressure Valve? Removed the turbo for the new up-pipes (International). The valve was closed and took a little bit of force to open. once we got it open, we could actually see where it was binding on the bottom. worked it manually several repititions and it worked smoother. Is this carbon buildup, and what is the best course of action. good news was the turbine blades looked fine.
thanks
thanks
Lead Driver
Joined: Oct 2004
Posts: 7,413
Likes: 1
From: Columbia, MO
Does it stick when you drive it? The way it's situated on the shaft, exhaust pressure should push it open. You could try to scrape the carbon out of there to see if it helps. IIRC, Kwikkordead had a problem with a sticking EBPV a few years ago. You might PM him if he doesn't chime in here.
Senior User
Joined: Jul 2005
Posts: 348
Likes: 1
From: Memphis, TN
The EBPV will do its thing ....parked or driving....until the truck is sufficiently warm. If you give it more gas or hit the brake it will shut off...only to come back on once you stabalize the gas pedal again. I've heard this is normal operation under certain temps. Mine only does it when cold and only for about 3-4 miles then I hear it kick off.
Lead Driver
Joined: Oct 2004
Posts: 7,413
Likes: 1
From: Columbia, MO
The only other thing I can figure is that the butterfly and it's housing are made of different materials, and may have a different expansion rate. When it's that cold out, the housing might shrink just enough so that when the valve closes and the butterfly starts to expand more quickly (due to it getting the direct blast of hot exhaust gasses) that it would stick shut. I would imagine after a few minutes and both metals have expanded enough it should open up and not stick anymore.
FWIW, the tolerances in these valves do change over time. When I put the van turbo on a few years ago, I started off with a brand new EBPV and it would close smoothly and seal tightly all the way around the bore of the valve. I had the turbo off a few weeks ago to replace the pedistal seals, and noticed that the butterfly no longer seals tightly to the bore of the valve. This is only after a few years of heat cycles, so I can imagine that as time progresses the variance between the butterfly and bore would only continue to grow larger.
If it begins to stick too bad, you might look into eliminating it completely.
FWIW, the tolerances in these valves do change over time. When I put the van turbo on a few years ago, I started off with a brand new EBPV and it would close smoothly and seal tightly all the way around the bore of the valve. I had the turbo off a few weeks ago to replace the pedistal seals, and noticed that the butterfly no longer seals tightly to the bore of the valve. This is only after a few years of heat cycles, so I can imagine that as time progresses the variance between the butterfly and bore would only continue to grow larger.
If it begins to stick too bad, you might look into eliminating it completely.
5th Wheeling
Joined: Aug 2007
Posts: 27
Likes: 0
what does the valve do? how can you tell that its working when driving? when i lift off the gas pedal and engine brake, the engine sounds like its not getting any fuel, and then if i just tip in on the throttle a little it sounds like its running again. is this that valve operating? thanks.
Lead Driver
Joined: Oct 2004
Posts: 7,413
Likes: 1
From: Columbia, MO
The valve simply closes under specific conditions to help the engine warm up faster by providing a little load on the engine. I believe it has to do with how cold the engine oil and ambient temperature are. If you start the truck on a cold morning, you might be able to hear a difference in the sound from the exhaust. It will be much less of a rumble and you might hear a whistling sound, especially if you have an aftermarket exhaust or a straight pipe.
When driving, it may close if it's exceptionally cold outside. What you've described sounds just like the valve closing while driving. There is a pressure sensor in the exhaust, the exhaust back pressure sensor, that senses when you've applied throttle due to the increase in backpressure in the exhaust system. When exhaust backpressure increses to a certian point, the valve will be commanded to open.
When driving, it may close if it's exceptionally cold outside. What you've described sounds just like the valve closing while driving. There is a pressure sensor in the exhaust, the exhaust back pressure sensor, that senses when you've applied throttle due to the increase in backpressure in the exhaust system. When exhaust backpressure increses to a certian point, the valve will be commanded to open.
