Dpf how does that work then ??

Phil1968

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Why do I have feeling that we're conducting the Turing Test here........?
My money's on it being a Sinclair ZX-81 that someone's managed to connect to the internet & it's become self-aware
 
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markjay

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Is that what I think it is and was illegal back in Turing's day?

I don't think so... :D

I was referring to this:

 

grober

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Hi Gang 2016 220d c class, I read a lot on here about dpf filters, can someone explain to me/us who don't have a clue. So add blue adds to exhaust fumes to help the planet I think and the dpf collects the soot so it dosen't go into the air I think? So if the dpf needs regen I gather that means self clean, How do you know if the car is doing it? How do you know if you have to take it down the motorway for a trip without having some sort of scanner? There does not seem to ba a warning light like my daughters range rover, If you had a star or another scanner do you run the car to regen or does that just reset the info? I am sorry for all the questions but as you can read I haven't got a clue how all this works. Mine is an auto so i thought i would drop a gear on the motorway for a blast to clean it out but after about 15 seconds it changes it back up, do i have to put it in sport for it to keep a lower gear to get the revs up? Or how do you keep a lower gear? Or then again does this not make any difference? PHEW lots of questions but i am sure i am not the only one who's lost with all this stuff. THANKS.
The DPF and SCR are 2 different exhaust clean up units
What is SCR? | Diesel Technology Forum
SCRGraphic-v3-nocaption_website_opt.jpg
 

Phil1968

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The DPF and SCR are 2 different exhaust clean up units
What is SCR? | Diesel Technology Forum
SCRGraphic-v3-nocaption_website_opt.jpg
That makes things very clear, I have a 2020 Vito van for work that uses AdBlue (First van with AdBlue I've had) & in my head I thought the AdBlue was injected into the DPF, but I can see from that diagram that you have a DPF separately in the usual fashion to catch particulates, with a separate catalyst that the AdBlue is injected into to lower NOx 👍
 

Tuercas viejas

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Is this a new urban myth that will soon be quoted on the 'net as gospel?
Is there even NOx created during re-gen given that NOx creation depends on a particular temperature pressure history?
Wikipedia >> Diesel exhaust fluid - Wikipedia makes no mention of AdBlue being specifically for re-gen. Rather, it suggests it is in constant use to counter engine-out NOx.
Well that is the issue ,the whole system is really hit and miss, coining my conclusion Blurrtech!

Back in 2009 I purchased at a US Gov surplus auction, was a diesel exhaust analyzer kit all in big blow molded cases for $250.
To my surprise it was a very expensive scientific set of diesel exhaust analyzer instruments.
Worth thousands of luverly US Dollars.
Of course we put it on a 2010 Blurrtec Sprinter.
What we saw and what MB claimed at least to American consumers was two different things and ultimately the class action lawyers got their teeth into it.
Whammo MB 1,5 billion dollar rectification fine.
Talk about truth in Advertising!!!

Now we can state that if you blot out the DEF injector you can see NOx go up through a few drive cycles with no fluid injected .
Traditionally we see that if the reduction has diminished to be around 60% the lights come on with prolonged use .
New sensors and DPF injection functioning before the AEM recall, gives about a 75% reduction WITH the DEF fluid being injected.
The reduction drops off over a few thousand miles to around 70%.
So far with the new AEM DPF installed with copper zeolites the reduction seems to be about the same but it doesn't seem to decay like the predecessors .
DEF usage seems to go up so the system is injecting more fluid more consistently for NOx control.

Of course emissions are often difficult to quantify due to all the varied operating conditions with different territories, fuel used and usage .
My business is lucky sited right at the the foot of the Continental Divide, and with three freeway lanes I can go to full power with a WOT.
Climbing from 6500 ft to 10500ft and watch the emission performance and heat generated in the exhaust SCR cat & Nox performance coming out of the DPF.
In contrast the UK being a small set of islands & heavily congested, with no really steep prolonged grades the exhaust temperatures and emission control activities will be entirely different due the factors much like being on the east coast like Boston & New York. So different operating conditions for sure !
Of course I haven't in all this mentioned the SCR Cat which is doing the burning (which its giving rise to the the term "lighting up") rather its chemical reaction. If it get plugged up then NOx and gases downstream are restricted so the system will detect low NOx flow elimination and put the lights on. Again the US AEM recall also includes a new SCR cat and NOx sensors for the OM642 engine.

To sum up the whole system does not eliminate NOx 100%, far from it, and at best its about 70%.
Now the MB OM642 engine and 2,1l only historically "enjoy' provisional emission approval in the USA, and MB pays the EPA $300 per platform for every one sold on these shores. That approval expires in 2022.
At that point we I think will see the demise of the V6 at least I am sure followed by the current 4 banger 2,1 engine .
Tuercas viejas
 
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markjay

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Having said that, you speak way better English that I speak your language!

Well, you should learn it then - can't hurt being able to read the Bible in its original language....
 

colinallcars

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Well, you should learn it then - can't hurt being able to read the Bible in its original language....
Reminds me of an American senator many years back objecting to issuing Spanish language bibles in schools, stating that they should only be issued in the original, English language form.
 

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