EGR valve
Thread Starter
Instructor
Joined: Feb 2005
Posts: 199
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From: Fountain Co
EGR valve
Just a couple questions. EGR valve and it's function? Can one of the pro's explain this to a newbe? Failure of the EGR will cause engine to run terrible? Thanks in advance.
Le Mans Master
Joined: Sep 2002
Posts: 5,236
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From: Myrtle Beach SC
Originally Posted by aocm77
Just a couple questions. EGR valve and it's function? Can one of the pro's explain this to a newbe? Failure of the EGR will cause engine to run terrible? Thanks in advance.
New Corvettes (C5 & C6) don't have EGRs due to the efficiency of the combustion process.
Burning Brakes
Joined: Feb 2004
Posts: 958
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From: In the Beautiful Shenandoah Valley of VA
Failure of the EGR will cause engine to run terrible?
Many people disconnect the EGR valve thinking that it will improve performance, but the reality is that this system only functions at part throttle to dilute the intake charge and lower NOx emissions. At wide open throttle the valve closes and should have no impact on performance.
Steve
Le Mans Master
Joined: Mar 2004
Posts: 7,493
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From: Little Rock AR
Originally Posted by Steve's74
The EGR valve is operated by vacuum, controlled in many different ways over the years. If an EGR valve fails in the closed position, the only drivability problem you may notice might be some preignition (spark knock). If it fails in stuck open position, or gets a chunk of carbon stuck in the seat, the engine will either idle rough or stall. It's also possible for the valve to open too quickly and cause a stumble or hesitation off idle in some situations.
Many people disconnect the EGR valve thinking that it will improve performance, but the reality is that this system only functions at part throttle to dilute the intake charge and lower NOx emissions. At wide open throttle the valve closes and should have no impact on performance.
Steve
Many people disconnect the EGR valve thinking that it will improve performance, but the reality is that this system only functions at part throttle to dilute the intake charge and lower NOx emissions. At wide open throttle the valve closes and should have no impact on performance.
Steve
As long as it is functioning properly, you will not mind having it. Stuck in open or closed position is bad. Loose the internal diaphram and you will get a vacuum leak and rough idle. If the valve dies on you, you can replace it or block it off but if you do block it, you should probably recurve the distributor. Rejet it if required.
-Mark.
