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http://www.outbacktravelaustralia.co...ddles-may-2016
"In most cases there isn’t an issue with this system, but there have been some spectacular failures: most notably Nissan’s horrible ZD30 three-litre diesel that will be consigned to history when the Patrol departs the scene in late 2016.
Interesting read. Cheers mate
I own a stock standard td42t. I bought a catch can some years ago but it's still in the box. I have never been tempted to soup her up even though i occasionally tow a 2.5t boat. It doesnt fly. It doesnt burn rubber. It doesn't turn heads. It doesn't drone. The clutch is still good. It pulls like a teenager. It may go for as long as i live.
Probably why I'll never win the Dakar in it. Dammit!
Whoa! All seemed well with this article until i got to the end and my BS meter went completely off tap. What can anybody tell me about this "calibrated, pressurised spray of crushed walnut shells" so espoused? Ive never heard of it. Does Nissan offer this service?
There are approved procedures for removing this buildup, most of which use a calibrated, pressurised spray of crushed walnut shells - I kid you not - to abrade off the carbon deposits at periodic intervals.*
Because of this carbon buildup problem there are many after-market suppliers providing blank-off plates for EGR systems. It's a sufficiently sophisticated supply chain to have model-specicifc plates on offer.
Claims made for engines with blanked-off EGR valves include smoother running, improved power and reduced fuel consumption. However, our research indicates that the only measureable benefits are reduced carbon buildup in the inlet manifold and no need to clean the EGR valve periodically.*
Before you blank off your EGR or re-map its operation, bear in mind that it's illegal to do so.
Some media blasting businesses use walnut shell fragments to blast so as not to damage the base metal (usually aluminum) of the part to be cleaned/blasted. Dont know about the calibrated bit though...
Agree. But does anyone believe Mr Nissan outsources this procedure for interval servicing of ZD30's? C'mon they're at the limit actually changing filters.Quote:
Originally Posted by AGman
Quote:
Originally Posted by Plasnart
Result of a quick google, there are plenty more;
http://walnutshellpowder.blogspot.co...gines-and.html
Just because you haven't heard of it doesn't mean it doesn't exist.
I know Allan personally, and also know he doesn't write BS in his articles. He makes a living doing this and his credibility is his major asset.
Happy to back away from last nights comment.Quote:
Originally Posted by macca
Cheers PlasnartQuote:
Originally Posted by Plasnart
Allan had mentioned the walnuts in another article, how the boffins find this stuff works for unusual applications amazes me.
The article Cuppa linked is fairly savage on a few mods we all have done or know of someone who has, some of it a bit risky to our expensive engines / legalities / insurance.
Nissan covering an engine control sensor with oil mist has to be one of the biggest stuff ups, no wonder some keep saying clean your MAF sensor when things aren't right under the bonnet.
I'll stick with my old school 4.2 slug thankyou. hahaha
One can of worms opened....
So air filter socks are bad, when they clog up. So is any air filter. Chips are bad, catch cans are pretty much pointless and EGR plates dont always do as we thought. Hmmm.
I actually agree with you there. No disrespect to macca, but I do think the author is a bit sensationalist in the article in regards to some of his comments.Quote:
Originally Posted by Plasnart
"We checked with a development engineer from General Motors about the need for catch cans on non-competition vehicles and he told me that if GM believed for one second that a relatively cheap part attached to the engine would improve reliability, limit warranty claims and reduce replacement costs, it would have been included in the PCV system"
I think it's a bit naive of him to accept this comment from a GM spokesperson. Experience has proven over and over again that most manufacturers will not spend $10 per vehicle to improve the longevity of it. My experience is the opposite, if they know a component will make a vehicle fail a few years out of warranty they will stick with it. I think he might be a bit too close to the manufacturers, they come down hard on dissent these days.
I am an engineer that's been involved in development projects and the bean counters and marketing wonks own the projects, you just build it cheap as possible and tow the line or lose your job.
I don't think he has a complete understanding of the EGR issues either. All the manufacturers are having these problems with their CRD engines, not just the ones he listed. Its not a carbon issue in the strictest sense of the word...its recirculated soot from the combustion process mixing with recirculated oil fumes from the crankcase, remove one or both of these things that shouldn't be in the inlet tract and you fix the problem.
I think the point Allan was making in the article is that the EGR system needs to be serviced regularly (every 40-60,000 km????). This could be a chemical clean such as the walnut shell treatment, EGR cleaner or taking the manifold off and manually cleaning. This becomes another service cost that I think most people wouldn't want to pay on a regular basis and are not aware off when buying a modern diesel.
As AGman said if you take away the soot, oil mist or both then the problem does not occur. The engine emissions however are not as clean
You are probably right, but he should come out and say it rather than this condescending article that assumes anyone who lifts the bonnet of their 4WD is a moron and has no right to do it.Quote:
Originally Posted by Rock Trol
You are right in that he puts his faith in the manufacturers designing a system that will meet emissions standards and last with minimal maintenance. Some engines may do this, others may not be designed as well. I think if manufacturers can get them to last the warranty period then that will be good enough for them. Not so much for us.Quote:
Originally Posted by AGman
The other thing he points out is that if you remap or chip an engine it is likely to increase the crank case pressure so you get more blow by. He strongly recommends against this. The problem is that most people will seek to increase power, especially if the engine is underpowered for the weight of the car. A lot of diesel 4WD's do OK out of the show room but as soon as you add the weight in the form of accessories they no longer cope. This is what has happened in my case. I did all the touring mods and then found the engine (ZD30 CRD) couldn't cope which put me on the expensive path of searching for more power. :(
It's almost enough to send a guy back to petrol engines.
Never!!!!:icon_driving:Quote:
Originally Posted by Rock Trol
I felt like this when I read this article, I actually didn't read the entire article as I didn't agree with the parts I had already read.Quote:
Originally Posted by AGman
I don't believe manufacturers would fit items that would help improve longevity. They want to produce vehicles that are legal and can be sold as easily as possible. To me this means, if it's good enough to comply with ADRs (I'm no expert here) and federal & state requirements that's as far as they'll go with it.
And all this scare mongering about this isn't legal and that's not legal, people do that to make themselves look authoritive and thereby acquire a a false sense of power that makes them feel that they can tell people off. I get tired of people telling me "you can't do that, it's illegal" mind your own business.
Often a case of shooting the messenger.Quote:
Originally Posted by 10G
I’m not taking a position on what Allan Whiting has written, but I do think you do some folk a disservice by taking the view you have expressed.
Simply telling folk that something is illegal only provides info, readers can make up their own mind about whether they will choose to comply with the law. It is quite common for folk to decide to do mods on the basis of ‘my mate did it’ without ever considering the legality. We need to be able to make fully informed decisions if for no other reason than knowing the level of risk/potential implications. Eg. the possibility of having an insurance claim denied because a vehicle is legally unroadworthy.
Eg.
Not so long back I posted a suggestion that it may be unwise to ‘advertise’ here on the forum that a poster had fitted an EGR blocking plate. The suggestion was derided by a few & subsequently ignored by some, which of course was their prerogative. All I did was suggest that posting that they had done this may not be in their own interests. No attempt to ‘tell people off’ or to ‘look authoritative’ but you could have thought otherwise based upon some responses. It’s not hard to write about it in a manner which doesn’t leave you open to unwanted consequences. Agreed some folk don’t like being ‘told’ anything, but some could also try to recognise that sharing info is different to telling people what to do. I can’t help thinking that sometimes chips on shoulders act as filters to well meant actions.
I absolutely 100% agree with all that Cuppa. My 'telling people off' comment wasn't aimed at anyone, sorry if made you feel uneasy or anything.Quote:
Originally Posted by Cuppa
I think I'm just fed up living in a PC (politically correct) world.
Not talking down to anyone, just think sometimes we forget or want to forget, as it may cost $$ or hurt our feelings
Engineers have alot of problems to deal with--
The bean counters.
keep design time to a minimum.
keep production time down.
Re use existing parts if available.
Deal with the ever changing emission rules.
keep the actual emission control device cost down.
And why build something that lasts a long time less profit in that.
Then there's the huge amount of competition to deal with making cars/trucks.
Now we see small changes at a time, to re-coupe "All" design and build costs.
even at times it doesn't realy work, we can update that next year and call it a new model!.
A sticky situation for sure, none of us grown ups like being told you can't do something.
We expect laws to protect us against the bad things , but something we can't see, has no effect to us personally,or then and there is --she'll be right mate.
Part the problem we're constantly being told by cleaver marketers "You can have this Now", but we usually forget, it is always at a cost one way or the other.
And then add in hundreds of different end users and conditions they are used in. Why do some engines have a fit and go into limp mode when you open the bonnet with an EGR Blocking plate in your hand while others dont even need an adjustment when they have every mod available fitted. Every engine is different even though it is of the same design and specification. We expect our design engineers to produce a "one size fits all" with all the constraints mentioned above, plus it must work forever and be economical to maintain and run. The article is well written and is a good read, but anyone who seeks to explain the grenade issue by linking it to one cause is in my opinion treading on very dangerous ground.Quote:
Originally Posted by Robo
No worries Matt, I wasn’t taking anything you (or anyone else) had said personally, I just chose to use a personal example that came to mind.Quote:
Originally Posted by 10G
I do feel similarly to you about unnecessary political correctness,(is their any other type?) but also feel that the term politically correct is one that is more often than not wheeled out to suit a perspective.
Just to stir the pot a bit more some might say that the legal requirement to ensure that their vehicle’s emission controls were in full working order is a result of ‘political correctness’. However we all know that vehicle emissions are increasingly bad for the planet. Nevertheless many of us , for example, choose to block our vehicle’s EGR valve. We do this out of personal preference but too often fail to acknowledge responsibility for this personal decision, instead blaming the law or law makers or even the ‘Greenies’ for being ‘political correct’ to justify our decision.
Silly question...
Has anyone done a NOx or CO test on exhaust post EGR blanking?
Just wondering how much difference EGR/no-EGR makes.
Seems a bit counter-intuitive to me to recirc hot, de-oxygenated air back in to get better results.
I think testing equipment is not common so most people wouldn't have tested, especially if its tested by a govt dept which then makes them fix the emissions if they fail. NOx is created at very high combustion temperatures so they route the exhaust back into the intake to lower these temps at certain times. It's a natural part of diesel combustion so high Nox doesn't mean that the engine is not working efficiently. The problem is that NOx is toxic to humans/environment so they are trying to restrict the amount that comes out by a method that isn't very healthy for the engine when mixed with oil vapour.Quote:
Originally Posted by RossKal
Cheers @Rock Trol
I have previously had access to an exhaust gas tester, but well prior to me knowing about EGR unfortunately. If opportunity comes up again, might undertake a little"speriment" (if I can find an EGR motor handy... not much use on my td42!)