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:) Does anybody no what the egr valve does. I took my truck in for servicr with rogh idle while in drive with foot on brake. The dealer said it was bad. Tnanx for any info
 

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Exhaust Gas Recycle

Allows the exhaust to be recycled back into the combustion chamber. IIRC
 

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I believe that since variable vane technology eliminates the need for a blow off valve the egr is a back up if the vane controller fails.

Could be wrong, but this is my story.
 

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lb7 does not have VVT(varible vane tech), may be clogged staying open, could try carb cleaner unless egr valve motor is fried. might be able to install egr blocker plate, read and search on egr.
 

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lb7 does not have VVT(varible vane tech), may be clogged staying open, could try carb cleaner unless egr valve motor is fried. might be able to install egr blocker plate, read and search on egr.
DUH. I did not see that It was an LB7. So does the LB7 have a BOV?
 

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I believe that since variable vane technology eliminates the need for a blow off valve the egr is a back up if the vane controller fails.

Could be wrong, but this is my story.
Sorry, WRONG!!:(

EGR = Exhaust Gas Recirculation - This is used to cool down the combustion temperatures and reduce NOx emissions. It is NOT intended to control the turbo back pressure.
 

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Sorry, WRONG!!:(

EGR = Exhaust Gas Recirculation - This is used to cool down the combustion temperatures and reduce NOx emissions. It is NOT intended to control the turbo back pressure.
Correct, it reduces emissions by recirculating the exhaust. The reason for this is to burn any unburned fuel that is still remains in the exhaust from the first process.
 

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Fine. Still does not answer my question regarding a safety to a malfunctioning vane. I put this question to the dealer and they told me the EGR is the safety.

Need more on this:Insane::Insane:
 

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Fine. Still does not answer my question regarding a safety to a malfunctioning vane. I put this question to the dealer and they told me the EGR is the safety.

Need more on this:Insane::Insane:
There is no safety to a malfunctioning vane; trust me the dealer is wrong.:) You get a check engine light, and/or a boom/whining noise if the vanes malfunction. In my case when I blew my turbo all I got was a loud WHINING noise. No check engine light, no nothing.

The EGR is purely for emmissions control reasons, as RayMich said.

None of the Duramax's (LB7, LLY, LBZ) have blow off valves.

Lastly, I would NOT use carb cleaner or anything like that in any part of the intake. If the engine inhales carb cleaner, you could get a runaway engine OR the glow plugs could ignite the vapor and you may have an explosion and/or terminally damaged engine.:)

Ben
 

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Ok then. My egr has to go. I am getting that "turbo bark" thing once in a while and do not want the January 06 reflash. I am reading that the new flash is a band aid and effects overall performance.

Looks like a EGR block off for me:D. Thank you all for the clairification.
 

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you'll need a Fingerstick unless you want possible reduced performace and/or a constant Check engine light...
 

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thanks, I knew about the stick. I just posted a new thread about the dealer January 06 reflash to stop turbo bark. they actually keep the EGR closed during shifts. I heard problem of bark gets solved but performance is compromised.

What is your take on this? I need to do something to eliminate the occasional bark. http://dieselplace.com/forum/showthread.php?t=70218
 

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The EGR valve allows Exhaust Gas Recirculation during idle and certain cruise events, in order to improve emissions by lowering combustion chamber temperatures by introducing recycled exhaust gasses back into the intake, diluting the fresh combustible intake charge with non-combustible gasses.

The EGR system on an LB7 is vacuum actuated by a series of vacuum solenoids. An engine mounted vacuum pump creates the neccessary vacuum for the system. There is also a butterfly similar to a choke-plate in the intake manifold that closes during EGR operation, causing an intake vacuum, sucking the gasses back into the engine.

When the dealer is done replacing the EGR, and it still idles rough, have them replace the Fuel Pressure Regulator, a more likely culprit in a rough idle concern.;)

And you LLY guys, let's keep this on topic, shall we?:D

:) Does anybody no what the egr valve does. I took my truck in for servicr with rogh idle while in drive with foot on brake. The dealer said it was bad. Tnanx for any info
 

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Can the egr be blocked off on the LB7 with out side effects?
 

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Yes, but you will have a constant check engine light.
 

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The EGR valve allows Exhaust Gas Recirculation during idle and certain cruise events, in order to improve emissions by lowering combustion chamber temperatures by introducing recycled exhaust gasses back into the intake, diluting the fresh combustible intake charge with non-combustible gasses.

The EGR system on an LB7 is vacuum actuated by a series of vacuum solenoids. An engine mounted vacuum pump creates the neccessary vacuum for the system. There is also a butterfly similar to a choke-plate in the intake manifold that closes during EGR operation, causing an intake vacuum, sucking the gasses back into the engine.

When the dealer is done replacing the EGR, and it still idles rough, have them replace the Fuel Pressure Regulator, a more likely culprit in a rough idle concern.;)

And you LLY guys, let's keep this on topic, shall we?:D
Does my 2002 LB7 have this EGR system?
 
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