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Old 4th December 2007, 11:05   #21
Jules
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Quote from Rincewind:
"Then for OBD purposes, we have to fail the system or by-pass it to see if the system falls within the OBD limit requirements in this instance, it's fully open like a by-pass system would be."

There are a few definitions I have to point out here:
A bypass system cannot be the same as an EGR held open.
As I understand it, a bypass "tube" completely blocks off any possibility of exhausted turbo gases re-entering the combustion

I'd like to see the emission figures done with the bypass "tube" fitted instead of the figures given above for an EGR valve held open. I'm sure that 457% NOx figure would be no where near as bad.

Finally how many EGR valves actually get cleaned in the car's lifetime by their owners or garages do you think?
Probably less than 10 %

So the 90% of clogged up (and many stuck open) EGR valves being driven
round the country are actually polluting our planet by that 457% NOx figure!!!
It can be concluded then that the device is best removed

Oh and well said Zeb in post # 16
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Old 4th December 2007, 13:03   #22
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Quote:
Originally Posted by julesbass View Post
Quote from Rincewind:
"Then for OBD purposes, we have to fail the system or by-pass it to see if the system falls within the OBD limit requirements in this instance, it's fully open like a by-pass system would be."

There are a few definitions I have to point out here:
A bypass system cannot be the same as an EGR held open.
As I understand it, a bypass "tube" completely blocks off any possibility of exhausted turbo gases re-entering the combustion

I'd like to see the emission figures done with the bypass "tube" fitted instead of the figures given above for an EGR valve held open. I'm sure that 457% NOx figure would be no where near as bad.

Finally how many EGR valves actually get cleaned in the car's lifetime by their owners or garages do you think?
Probably less than 10 %

So the 90% of clogged up (and many stuck open) EGR valves being driven
round the country are actually polluting our planet by that 457% NOx figure!!!
It can be concluded then that the device is best removed

Oh and well said Zeb in post # 16

Thats exactly what I was getting at!!! and from the information given by rincewind you can see that the particulate matter has increased too(with the EGR open) as I said.

A more effecient tuned engine can provide better economy if you don't use all the extra power!!! (Good fun at times though!). Better economy equals less pollutants released, probably lowering the total emissions by more than the small amount of extra NOx that the bypass would cause.

The small increase in the my fuel economy is a result of the combined effects of all the mods done to the car not just the Egr bypass.

JDC I'm with you on this one. There's lots of people getting rich on the back of recycling and environmental cost and taxes and it's at the financial detriment to the rest of us. The effect of which will make our remaining industries less competetive. The Chinese are building thousands of coal fired power stations with no emmision control (which is possible) to maintain their industrial growth. The U.S. foresaw the effects of environmental cost on it's industrial competetiveness which is one of the reasons it didn't sign up for Kyoto and it's slow uptake on environmental issues.



Russ.

Last edited by BigRuss; 4th December 2007 at 15:45.. Reason: spelling
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Old 4th December 2007, 14:28   #23
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Quote:
Originally Posted by julesbass View Post

This is admittedly about a Ford Galaxy 1.9Tdi, but I wonder if this would apply to 75 ZT owners who have disabled their EGR or fitted a bypass.

"On TDIs, EGR valve should open to allow carbon dioxide, which acts as a cooling gas) into the combustion chambers when the engine is under load (>30% boost). This allows the combustion chamber temperature to drop and thus the temperature of the exhaust gases. If it sticks in the closed position the exhaust gas temperature will rise causing a) the turbo bearings to fail and b) engine oil into the induction system. This can cause the engine to run on its crankcase oil until it is either stalled or goes bang. Problems with EGR valves in TDI engines are often the cause of rough running when the valve is stuck in the open position as well. In several cases turbos have blown but the EGR valve has not been replaced. Inevitably the new turbo unit will not last long."

Come on technical bods, lets have some more clarification on this subject!
There are some very valid points there if taken in the context of VW Group (as fitted in Galaxy TDi) and Renault diesel engines. Both the VW and Renault 1.9 TDi family of engines are very sensitive to blocked EGR systems. Lagunas and Meganes with the 1.9 and 1.5 DCi engines have a failure rate that would make you think they were fitted with chocolate turbos. But in truth, it is not the EGR system, or lack of one in the case of a bypass being fitted that is to blame. It is more a case of the inherent lack of long-term reliability and low operating tolerances of the particular breed of Garrett VNT turbo that is fitted to these engines.

The M47(R) engine is not hamstrung by this problem. Our Mistsubishi Industries turbo is as reliable as they come. I can recall many instances of 320d's, Lagunas, Golfs and Passats suffering from turbo failure. The Laguna in particular commonly consumes its engine oil through the turbine seals on an expired turbo leading to complete destruction of the engine. I have not heard of a single instance of turbo failure on a 75 or ZT. They have undoubtedly occurred but it certainly can't be considered a common or even infrequent problem.

In my opinion, the design and components of the 75/ZT diesel intake and exhaust system are of sufficient quality and reliability that bypassing the EGR has no detrimental effect to reliability whatsoever. The 320d may have had 150bhp as standard but they are known to be far less reliable as a consequence of the turbo fitted to generate that extra 15bhp.

Mod away fellas!!!
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Old 4th December 2007, 14:29   #24
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To julesbass, Zeb, JohnDotCom, bigruss42

How on earth have you concluded from Rincewind's excellent information that bypassing the EGR has improved things?

His first and better set of readings are with the OBD system fully connected and the EGR working.

His second and worst set of readings have been taken with the EGR disabled, such that it never opens, and thus behaves like a bypassed EGR ie with NO injection of exhaust gases

To me, this only goes to prove that a good EGR system, can offer many advantages, not least of which is the vast reduction in NOXious gasses.

To me it's not an argument to compare you disabling the EGR with power stations in China.
The whole point about NOX reductions, is that they pollute the immediate environment. In areas of slow moving traffic, the engine is at part load and this is when the most NOX gases will occur.
So when you are crawling along, look across to the driver next to you, and just think you might be killing him/her as well as yourself.

This seemingly cavalier attitude at putting two fingers up to environmentalists, seems so selfish it is beyond belief. To even suggest that people are making money out of the green issue, while it is OK for people to peddle half baked and dangerous ideas, is really taking the biscuit.

It is only because of our very lax MOT, that enables you to get away with this.
Try it the USA, where most of the emmisions regs were born. I would think tampering with anti-polution devices would be illegal.

Thankfully, as some you may have read, EGR systems involving partial opening of the exhaust valve during induction are under development. Try disabling that!

And, as already been alluded to, it seems the main protaganists are the toys for boys brigade - enough said.

Colin
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Old 4th December 2007, 14:31   #25
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olin... I am not sure you and we are even reading the same thread.....I haven't drawn any conclusions from Rincewind's post....as to a cavalier attitude....I would suggest it is not a question of two fingers to environmentalists but it is a question of seeing many many companies hijacking green issues for profit...Prius anyone? When the EGR is closed it still does not behave the same as with the bypass fitted because said bypass does not restrict airflow whereas the Egr most certainly does.

Last edited by Zeb; 4th December 2007 at 14:36..
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Old 4th December 2007, 14:38   #26
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Quote:
Originally Posted by Zeb View Post
olin... I am not sure you and we are even reading the same thread.....I haven't drawn any conclusions from Rincewind's post..
Appologies if I mistakenly included you about Rincewinds post on his testing. However, it would be interesting to hear your views on his findings.
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Old 4th December 2007, 14:43   #27
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Quote:
Originally Posted by ColinW View Post
Appologies if I mistakenly included you about Rincewinds post on his testing. However, it would be interesting to hear your views on his findings.
Colin
They provide food for thought, however, I would be keen to have a bypassed car emission tested against one that is standard and serviced as per the handbook. I suspect the differences might not be what people would expect.
My car is more efficient with egr bypass and does better mpg as checked over 10,000 miles. So any adverse increase in NOX etc is balanced by the fact that I am using less diesel in the first place and also, most importantly, releasing less particulates into the atmosphere - which I believe to be just as much of a danger as Nox...
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Old 4th December 2007, 15:44   #28
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I have now done nearly 20,000 miles with mine.
i have less smoke since removing it,
Ask Kandyman and julesbass who have previously experienced driving in my Wake of smoke,
now hardly any at all.
My MPG is far better than before and I have no faults being logged on T4 and as said have just passed MOT.
As to the Green issue, if I wish to put two fingers up to it so be it,
and frankly I don't give a dam.
In the US which I am in more than out, you would be so surprised at Modifications etc carried out.
Older vehicles can choke you to death following them with the black NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD- coming out.
People over there regardless don't give a Dam about Green Issues where I go and will continue to run Air con everywhere 24 Hours a day even when not in, all the lights and flood-lights left on, cars that drink Fuel quicker than you can fill up over here.
They almost riot when it hits £1.23 per Gallon!
The US only Tax fuel at 39 Cents per Gallon!
So like a large Majority of people,
I buy the Things,
I use the Things
I will do what I want with anything within the Law of that Country.
And that is that.


PLEASE NOTE THIS IS IMHO AND DOES NOT REFLECT ANY VIEWS OF THE CLUB

Last edited by JohnDotCom; 4th December 2007 at 16:00.. Reason: Spelling
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Old 4th December 2007, 15:54   #29
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Quote:
Originally Posted by ColinW View Post
And, as already been alluded to, it seems the main protaganists are the toys for boys brigade - enough said.

Colin
On the contrary, altoghether too much said in my opinion, Colin.

Surely, if you wish to make a valid point or continue a balanced discussion,it is better to do so without making a sweeping and unjustifiable statement which will probably alienate the very people you are trying to convince?
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Old 4th December 2007, 16:07   #30
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I quite like having toys and, whilst the comment may have been meant to allude to a particular mentality (and imply a limited intellect) such stereotypical and sexist perceptions are in the eye of the beholder...
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