The original daewootech forum

Daniel · Post by **Daniel** » Tue Dec 14, 2004 3:10 pm

Hi,
Doe's the EGR valve need regular maintenance?
Thks,
Daniel

MMamdouh · Post by **MMamdouh** » Tue Dec 21, 2004 9:13 pm

"regular"??... non whatsoever. it is actually a very simple device that simply will be in one of two conditions: 1) working or 2) not working so you don't have anything to maintane here.

MMamdouh

bluesheepbrian · Post by **bluesheepbrian** » Wed Dec 22, 2004 3:14 am

What is an EGR valve?

daewooluvr · Post by **daewooluvr** » Wed Dec 22, 2004 6:59 am

E xhaust
G as
R ecirculator

MMamdouh · Post by **MMamdouh** » Wed Dec 22, 2004 10:30 am

here is more info on what the EGR do.

The exhaust gas recirculation (EGR) system is used on engines to
lower NOx (oxides of nitrogen) emission levels caused by high
combustion temperature. The EGR valve is a duty control linear type
that is operated by the powertrain control module (PCM)/engine
control module (ECM). The EGR valve feeds small amounts of exhaust
gas into the intake manifold to decrease combustion temperature. The
amount of exhaust gas recirculated is controlled by variations in
vacuum and exhaust back pressure. If too much exhaust gas enters,
combustion will not take place. For this reason, very little exhaust
gas is allowed to pass through the valve, especially at idle.

Too much EGR flow tends to weaken combustion, causing the engine to
run roughly or to stop. With too much EGR flow at idle, cruise, or
cold operation, any of the following conditions may occur:
- The engine stops after a cold start.
- The engine stops at idle after deceleration.
- The vehicle surges during cruise.
- Rough idle.
If the EGR valve stays open all the time, the engine may not idle.
Too little or no EGR flow allows combustion temperatures to get too
high during acceleration and load conditions. This could cause the
following conditions:
- Spark knock (detonation).
- Engine overheating.
- Emission test failure.

MMamdouh

daewooluvr · Post by **daewooluvr** » Wed Dec 22, 2004 5:33 pm

mmamdouh wrote:Too little or no EGR flow allows combustion temperatures to get too
high during acceleration and load conditions. This could cause the
following conditions:
- Spark knock (detonation).
- Engine overheating.
- Emission test failure.

Is this actually true or just something you've heard?
Think about it, how did cars manage to run before EGR.
I would like to eliminate EGR on my engine and I honestly can't see why it would cause the Engine to get to the point of overheating. With proper coolant and airflow through the radiator you should be fine. But that's just my opinions. I'd like to see some facts.

DomWoo · Post by **DomWoo** » Wed Dec 22, 2004 6:10 pm

actaully removing the egr valve is something alot of people do, i dont remember where i read it but a guy was rebuilding his engine and decided to weld up the egr valve hole because the car was not going to be street legal anyways because of all the stuff he had on it so... i think that its not true, i also read that the egr valve is mainly for start up because nothing is warm so emissions are high

MMamdouh · Post by **MMamdouh** » Wed Dec 22, 2004 7:30 pm

daewooluvr wrote:
mmamdouh wrote:Too little or no EGR flow allows combustion temperatures to get too
high during acceleration and load conditions. This could cause the
following conditions:
- Spark knock (detonation).
- Engine overheating.
- Emission test failure.
Is this actually true or just something you've heard?
Think about it, how did cars manage to run before EGR.
I would like to eliminate EGR on my engine and I honestly can't see why it would cause the Engine to get to the point of overheating. With proper coolant and airflow through the radiator you should be fine. But that's just my opinions. I'd like to see some facts.

i heard that and experiance it too... i mean experianced the EGR kicking in.

that was under high ambiant temp. some 45C or so and during hard acceleration on fiftht gear with the A|C on and a passinger along side so that was really a load on the engine and it has all the right to start overheating... that's when the EGR kicked in and i felt the engine started to sputter a little and it did not accelerate anymore... that was not the rev limiter i was way under the red zone.

it seems the EGR kicks at the times where the engine rapidly overheats during acceleration undre loads, that rise in tempreature is just for the time of the acceleration and not during the whole operation period of the car.

my point is an engine that overheats at idle will not trigger the EGR... only hard acceleration and the correct conditions will triger it, after all it works throught the vacuum in the intake and with all things beeing even that vacuum should be alot to operate it.

my car never heats up nor sputter so that was the EGR, also my EGR produces some sound when its diaphragm moves and i heared it too, also all the time that i have experianced the EGR was nearly similar to the conditions mentioned before.

i also wanted to remove my EGR but what if same condition occured again?? (hard acceleration + hight temps + ...etc) will that hurt the engine if the EGR was supposed to interfer but it was not their to do the job? in other words is detonation that bad??

MMamdouh

DomWoo · Post by **DomWoo** » Wed Dec 22, 2004 8:56 pm

maybe my egr valve doesnt work like yours... because i drove through vegas heading into california in auguest at noon and it was 118'f out with the ac running and doing about 90 - 100MPH and my car did not lose power, sputter or overheat. and i drove like that for a long time.

MMamdouh · Post by **MMamdouh** » Thu Dec 23, 2004 7:59 am

WooHoo wrote:maybe my egr valve doesnt work like yours... because i drove through vegas heading into california in auguest at noon and it was 118'f out with the ac running and doing about 90 - 100MPH and my car did not lose power, sputter or overheat. and i drove like that for a long time.

try flooring the gas pedal to let the car accelerate to its top speed at those same conditions... i bet that will trigger the EGR.

MMamdouh

Daniel · Post by **Daniel** » Thu Dec 23, 2004 8:15 am

Thanks for your replies. In fact it was after visiting http://opel-vectra.com/pages/accueil.php that I had some fear. The EGR's pictures are self-speaking

. But it seems now that only gasoil engines are concerned not ours. Anyway if I feel some strange engine running that you have described I have a direction to look at for.
Merry Christmas and happy new year.
Daniel

DomWoo · Post by **DomWoo** » Thu Dec 23, 2004 2:54 pm

i was flooring it... there is some big hill going into california.. .and my foot was on the pedal all shes got... trying to keep up with all the people going 120mph, i didnt dare to take my car that fast as for my tires just got repaired from a big ass nail