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You and your EGR valve ...

published: 01/12/06, 20:59
by abyssin3
As most know, this valve was designed to reduce NOx, which works +/- well, in any case when the vehicle is new. It's when she gets dirty / mouths that the controversy comes ...

So to take a look at the benefits / evils of the EGR valve for diesel on 1 ° the environment and 2 ° the cleanliness of the engine, conso, longevity, etc. I invite everyone who has one day disconnected changed, reconnected, or even ignorant of putting on this post his observations on this terrible object, before and after having made its modifications.

published: 01/12/06, 23:41
by daraq
Hello, I can not say exactly if it's effective or not. All I can say is that it is a source of confusion.
I have to clean the mien and it may well be that, once I am broken, if I find a hose of the right diameter, I am going to make it more difficult for someone to tell me that it is ecologically effective.

published: 02/12/06, 01:22
by abyssin3
Actually, I unplugged mine from ~ 10.000Km. Since then, it is turning better and better, which is not surprising when I saw the accumulated soot package that crumbled regularly going into the engine.
Seeing this I really wondered what was the air filter, as the coonnonnie that the EGR brings is much more important.
The only interest I see there is to connect the arrival of doping to water eventually.

published: 02/12/06, 02:43
by Other
Hello,
on a new diesel engine it passes again, but if the engine has good wear so the oil vapor that comes out of the breather, it presses to condemn this valve, or restart the engine.
I explain the oil vapors coming out of the breather are sent into the intake and when we add the soot ERG valve it is a black mud in the intake manifold that reduces the passage of air and decreases performance of the engine and all this provided that the ERG valve works correctly (not that it remains open).
On a petrol engine it is quite different
First the ERG valve and more reliable and work even after 15ans and 280000km. the exhaust gases have less soot than the diesels and the quantity of reinjected gas is less (it is sufficient to examine the size of the small holes for the gases)
I did ERG valve tests on multipoint petrol engine (Buick)
just disconnect the circuit so that the valve always remains closed.
The engine temperature increased as well as consumption, the latter finding my surprise I expected on the contrary.
On the diesel fuel consumption it was slightly improved the engine was more worn.

Personally I think that the ERG is not yet well mastered, and that it has been introduced in automobiles in a hurry just to meet NOX standards. Although this system dates from the end of the 1970 years in America, when we look at different models, some is simply an off with a rustic modulation, while other GM Cadillac engines, Buick has a sophisticated ERG modulated with several modules of different size.
And I think it's a bit like the panton it takes a good dosage for it to be effective.

We are better to get used to the ERG valve that will become a necessity for the new engines to work cold ...
And for me a motor that works cold (exhaust and little heat loss in the cylinder head) is a motor that has a good performance.

Andre

published: 06/12/06, 19:19
by Colmant
I would like to know what it is and where it is
please

published: 06/12/06, 20:41
by Woodcutter
EGR: Exhaust Gas Recirculation or Exhaust Gas Recirculation Valve, in French.
It's a system that controls the passage of some of the exhaust that is recycled to the intake for (if I remember correctly) lowering the combustion temperature and thus producing less NOx.

published: 06/12/06, 21:03
by Christophe
Woodcutter wrote:and thus produce less NOx.


and more imbrulé : Mrgreen:

published: 06/12/06, 21:39
by Woodcutter
Christophe wrote:
Woodcutter wrote:and thus produce less NOx.
and more imbrulé : Mrgreen:
In theoretical operation, I do not think ...

In reality, I have a doubt, why?

published: 06/12/06, 23:01
by bolt
Woodcutter wrote:EGR: ... a part of the exhaust gas that is recycled for admission to (if I remember correctly) reduce the combustion temperature and thus produce less NOx.


I wonder if this is not noises that courrent :!:

Logically, if we re-injects gas exch. They are cence be hotter than air from the air filter

the principle is a vicious circle (or stale if you want : Mrgreen: :

like that recycles :P

The fact to recycle a portion of gas exch. limit the production of NOx, mainly by the fact that part of these gases is of NOX, and that this NOX cannot become NOX and a half: nitrogen, once oxidized, cannot oxidize any more, whereas if the engine swallows "brand new" nitrogen, this "brand new nitrogen" "he can do it (oxidize)

but it can not be recycled when the engine is partial loadBecause it is essential that swallows O2 enough to occupy all the fuel that made him drink (otherwise unburnt : Evil: )

But everything here has nothing to do with a decline of T ° of combustion, in contrast, partial load, it is preferable to increase the temp of combustion for better fuel burn

In any case, there must be full load of recycling
at least there is a load, the more can be recycled:
1) causing swallow N NOX already become so inconsequential (as mentioned above)
2) fuel is more apt to grab oxygen, if the engine does not swallow too much, there is less available to take nitrogen

That said, and here has nothing to do, no burning ° T is high, the more nitrogen happens to bind oxygen to produce NOX, but here is the T ° maximum performance Full Load:

maximum efficiency at part load, T ° does not rise too much, while at full load (While the fuel is CENCE take all the oxygen) the temp rises so high that the nitrogen comes to poking fuel to oxygen (the Brigant)

to sum up :
partial load: recycling to reduce NOX, although some increases here the T °
at full load: delay in the injection, which mainly reduced the maximum T ° to reduce NOX (but necessarily increase the specific conso : Evil: )

they may also delay a little injection at partial loads, I do not know, must see the T ° in play

bolt

published: 06/12/06, 23:18
by PITMIX
Hello
I want to answer questions 1 and 2 of the poll, it is not possible ?? : Cheesy: : Cheesy:
The mechanics conceal the EGR valves which pose too much problems on the turbo Diesel but at the same time when this valve functions correctly it allows an efficient depollution.
The question is, is the EGR valve really essential on a TD knowing that when it locks the car spits Pharaonic smoke?
Is Pantone not more effective in this area?
Finally a Pantone with partial recycling of the exhaust is an improved EGR valve.