EGR mod on d40

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Could you trick the valve to close by modifying the harness?

Stu

I'll take a punt and say "not easily", because the ECU is constantly checking the state of the valve. You'd have to know what kind of signal it was sending, and what kind of signal it expects in return, in order to be able to fool it.

Blanking off the pipe by replacing a gasket with a solid piece of aluminium not only stops the gases getting through, but allows the valve to operate normally and the ECU is no wiser about it.

It'd also be quite hard to spot during maintenance as I really doubt Nissan - or any mechanic, really - would pop open the EGR pipework to inspect it.
 
Hmm interesting... I'm and aircraft electrical maintenance engineer so it's my nature to look at the wires before I get my hands dirty :D
 
After reading this thread in full , I ended up making a plate from 1.5mm S/steel I had , now my D40 has always blown black smoke from day one , adding the LPG system halved the smoke , When I blocked the EGR off the first thing I noticed was better spool up and zero smoke, 400km's on and the economy hasnt really changed and turbo lag is nowhere as bad as it used to be , it worked for me and the ECU is throwing no codes

Cheers Marty
 
Is the EGR in the Same place for a 2010 ST D40 as I had a look at mine today and looks differant fromt eh images that have been posted?
 
I thought it was the same engine. Look for a metal tube about 25mm in diameter heading around the front of the engine (it has to come from the exhaust around to the inlet). It should be up around the top so that it doesn't travel too far from the manifolds.
 
I thought it was the same engine. Look for a metal tube about 25mm in diameter heading around the front of the engine (it has to come from the exhaust around to the inlet). It should be up around the top so that it doesn't travel too far from the manifolds.

Yeah I thought so, but the pictures posted look different?

Any one got some clearer pics with arrows?

Cheers
 
have had mine blocked off for a week now and seems to have done the trick, the tailgate is no longer covered in black soot.
 
have had mine blocked off for a week now and seems to have done the trick, the tailgate is no longer covered in black soot.

I realise that as far as the law goes, this is anecdotal evidence (because it was not performed by an official organisation specialising in testing emissions) but I have to ask this question because it just makes me wonder...

If blocking the EGR reduces the emissions, why on earth do they connect the ruddy thing in the first place, and why aren't we ALL blocking the thing off?

Australian law requires that any changes made to the vehicle do not make the emissions worse - we are allowed to improve it, but we are not allowed to remove any part of the system that might cause the emission levels to increase.

But you have to wonder, if everyone that's blocked the EGR off has reported a DECREASE in emissions, why this wouldn't fall into the category of "improving the emission control" therefore making it a legal modification?

I'm sure I read somewhere that the EGR was introduced to assist in more complete combustion of the fuel. However, it's only ingesting a very small amount of the actual output, and in doing so it is INCREASING emissions according to these reports here, which are not strictly scientific but are more reliable than coming from an organisation that's been instructed to provide a certain answer (Mulder, we need you!).

Is it possible that it's just there to inhibit the output of the motor, so that next year Nissan can remove it and claim 20Kw improvement in power?
 
But you have to wonder, if everyone that's blocked the EGR off has reported a DECREASE in emissions.......

i don't think anyone has reported a DECREASE in emissions. after all how many ever get tested?
what you will find is that with it blocked Nox emissions will go up but soot and other emissions go down. EGR systems are there to lower Nox but it increases other emissions and soot, hence the need for cat's and now soot filters.
 
i don't think anyone has reported a DECREASE in emissions. after all how many ever get tested?
what you will find is that with it blocked Nox emissions will go up but soot and other emissions go down. EGR systems are there to lower Nox but it increases other emissions and soot, hence the need for cat's and now soot filters.

I was considering the whole issue from an anecdotal perspective not an officially tested POV, as I'd said in the preamble. But in this post that I'd quoted, "the tailgate is no longer covered in black soot. points squarely at "less emissions". This post from Martin states "When I blocked the EGR off the first thing I noticed was better spool up and zero smoke" ... the anecdotal evidence is there.

I am not sure that the EGR is actually going to catch the nitrogen emissions anyway, with over 90% of the exhaust gas passing straight through to the rest of the system. I fail to see the reason why they're capturing a small percentage of the exhaust and claiming to be able to do anything, when the result of including the EGR is to create more smoke, soot and reduce power!

It would be interesting to see an official test of emissions with and without EGR. According to this web page on EGR, the system is designed not to reduce NOx levels in the exhaust stream, but to cool down the combustion temperature.

That's curious in itself, because a cooler combustion is going to mean less complete combustion and thus the need for a DPF. Remove both and win?
 
Everyone that has done it here has reported a decrease in VISIBLE emissions, by VISIBLE I mean to the naked eye.

EGR is designed to reduce the combustion temps which will reduce nox emissions, this is the emission responsible for acid rain

Whilst not the be all and end all of information, wikipedia has a good explanation:

EGR in diesel engines
In modern diesel engines, the EGR gas is cooled through a heat exchanger to allow the introduction of a greater mass of recirculated gas. Unlike SI engines, diesels are not limited by the need for a contiguous flamefront; furthermore, since diesels always operate with excess air, they benefit from EGR rates as high as 50% (at idle, where there is otherwise a very large amount of excess air) in controlling NOx emissions.

Since diesel engines are unthrottled, EGR does not lower throttling losses in the way that it does for SI engines (see above). However, exhaust gas (largely carbon dioxide and water vapor) has a higher specific heat than air, and so it still serves to lower peak combustion temperatures. There are trade offs however. Adding EGR to a diesel reduces the specific heat ratio of the combustion gases in the power stroke. This reduces the amount of power that can be extracted by the piston. EGR also tends to reduce the amount of fuel burned in the power stroke. This is evident by the increase in particulate emissions that corresponds to an increase in EGR. Particulate matter (mainly carbon) that is not burned in the power stroke is wasted energy. Stricter regulations on particulate matter(PM) call for further emission controls to be introduced to compensate for the PM emissions introduced by EGR. The most common is particulate filters in the exhaust system that result in reduced fuel efficiency. Since EGR increases the amount of PM that must be dealt with and reduces the exhaust gas temperatures and available oxygen these filters need to function properly to burn off soot, automakers have had to consider injecting fuel and air directly into the exhaust system to keep these filters from plugging up.

EGR deletion
EGR deletion in diesel engines is considered justifiable by a wide range of people, including the environmentally conscious. Although deleting the EGR system results in increased NOx level; hydrocarbon emissions, particulates, carbon monoxide and carbon dioxide are drastically reduced. Furthermore, EGR deletion results in an increase in fuel economy as high as 25%. Exhaust gas recirculated back into the cylinders adds wear-inducing contaminants and causes an increase engine oil acidity, which can result in an inefficient, poorly running engine. The increased level of soot also creates the need for diesel particulate filters to prevent environmental contamination.
 
as mentioned above EGR reduces combustion temp so its below the temp nitrogen oxides (Nox) is formed. the downside side is because they are damping down the flame so to speak, it increases the amount soot produced and also the amount of CO and acids.

however even with EGR these motors should not be blowing smoke in the first place. i think our poor fuel makes the situation worse.
 
as mentioned above EGR reduces combustion temp so its below the temp nitrogen oxides (Nox) is formed. the downside side is because they are damping down the flame so to speak, it increases the amount soot produced and also the amount of CO and acids.

however even with EGR these motors should not be blowing smoke in the first place. i think our poor fuel makes the situation worse.

Another thing. I'm on LPG as well and my emissions should much lower when compared to a std diesel as the LPG has the tendency to complete the diesel burn in full
I also have no cad despite the vehicle fitted with them when they were released, at the time of my Nav 06 plate there was no ADR for having a Cad installed to diesels

Cheers Marty
 
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Hey Guys still deciding if i should do this mod to the ute or not ? Anyone got any updates on how their ute is performing after the mod and in their opinion is it worth doing ?
Cheers David
 
Wambat, I think there's a moral dilemma that needs to be answered in your own mind before anything else.

Is the modification to your emission control system (which is illegal and you can be fined up to $13,200 in NSW for doing it, if they discover it) worth doing? Why is this a "moral" dilemma?

Because you're balancing one form of pollution against 4 others. On the one hand, you are reducing NOx (oxides of nitrogen) by reducing the combustion temperature (note: doesn't happen all the time, the EGR valve is CLOSED at full throttle when it's burning the most fuel!). However, in doing so, you're consuming 25% more fuel, adding 25% more particulate matter to the environment, adding 25% more carbon monoxide and carbon dioxide etc.

The question is: do you want to reduce the vehicle's impact on fuel usage and its carbon footprint by 25%? They don't have a NOx filter yet, so you can't "replace it".

Since the EGR doesn't operate all the time anyway, it is really more of a gimmick to pass Australia's emission test anyway, so can you be justified in blocking it off?

I actually think there's a considerable argument in favour of blocking it. Burning 25% less fuel - which is a remarkable amount - could hardly be considered "bad", not only on your hip pocket but also in the exhaust (25% less total emissions). Reducing particulates (for the manual or any auto with the DPF removed) is also not unkind to the environment.

So, do you obey the law (the moral "right") and leave your EGR intact, or do you help out the environment and block it off? How much help is the NOx emission reduction anyway, overall, when the EGR system doesn't operate all the time?

In other words, just how bad would a person be, if they blocked their EGR system?
 
25% reduction in fuel useage?????

Who's had that achievement?
I've had mine blocked over a month, haven't noticed any significant difference in smoke or power. Fuel economy may have improved a bit but not enough to go singing and dancing in the streets.

Do some of you guy's dream up fantasy results to justify your mods or what??

I think it's a mod worth doing to stop the carbon going back through the motor, if you do get any gains in fuel useage then that's a bonus IMO. But to improve economy by 25% sounds very unrealistic to me.
 
Only way to know for sure is to hit the dyno, If those fuel savings are their they should show up in a massive power increase in the mid range where the EGR valve would normally be opened and operating.

The claims to increased off idle power or completely removing the turbo lag is unlikely and in my case false. I believe the reason is because the EGR valve is closed at idle and under full boost situations.
 
Thanks for the input tony and kingcab in my opinion the positives are out weighing the negatives on the info i can gather and at the end of the day its a cheap mod that can be easily returned to original condition if the gains are not significant. Anyone else got an opinion for or against this mod I'd love to hear it .
Cheers David
 
25% reduction in fuel useage?????

Who's had that achievement?
I've had mine blocked over a month, haven't noticed any significant difference in smoke or power. Fuel economy may have improved a bit but not enough to go singing and dancing in the streets.

Do some of you guy's dream up fantasy results to justify your mods or what??

I think it's a mod worth doing to stop the carbon going back through the motor, if you do get any gains in fuel useage then that's a bonus IMO. But to improve economy by 25% sounds very unrealistic to me.

I'm with you mate, I've had mine blocked for about 5000kms and haven't noticed any fuel reductions in the slightest, yes it blows less smoke, and seems to spool up a bit quicker, maybe!!!
But i agree that some people get a little bit enthusiastic with their results.
 

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