Technical AdBlu.. whassit do?

[Ralf S.]

What's that AdBlu stuff all about?

I know that some Mercedes' have a little reservoir that you can essentially urinate into (or Add Blue.. ) and that when it gets combusted (?) it produces ammonia, which converts NitrOx into water vapour and nitrogen.. but apart from that, how's it work?

It seems to be mostly water so how come it a) burns at all, and b) doesn't f*ck the fuel filter, and c) doesn't flood the exhaust with water...?

Does the car have to be adapted to use Blue? Ammonia is pretty nasty stuff if you sniff it, so I'm guessing it's just a bit corrosive. How does it not dissolve said Merc's cylinders or exhaust system etc?

What would happen if I put some in my old JTD (i.e. in time for the MOT test)? Would it make any difference or would it just dissolve my cylinders and exhaust system etc?


Ralf S.

 

[Eklipze3k]

As I understand it, the AdBlu doesn't go into the engine, but reacts with the exhaust gasses on the way out. So it's not as easy as just pouring some into your fuel tank as it's not part of the combustion process.

 

[chris3234]

The scr system fitted to lots of diesel's injects it into the exhaust to reduce Nox emissions
It's a separate system tho anything else so unless it's fitted at the factory you can't add it or anything like that

 

[RuSZ]

Adblue reacts with exhaust fumes. Kinda a replacement to a CAT.

Has to be put in a separate tank.

Can’t be used in a car not designed to use it as has special systems.

 

[sussexa]

there is the psa stuff
read this thread if you want to try something in your fuel.
fuel borne catalyst may be for you
https://www.alfaowner.com/Forum/tuning-andamp-upgrades/918530-jtdm-ways-to-increase-egt.html
there are other specialised additives that probably do or claim the same
like ar6200 for example
https://www.powerenhancer.co.uk/archoil-ar6200-fuel-modification-complex-high-concentrate-3946.html
i never noticed much if any difference but i have no dpf
tried many things over the years this has been now worse than anything else and i dont do enough milage to prove any mpg gains.
i ran this sometimes on its own sometimes in mix with inj cleaner
sometimes i just run straight cetane booster and inj cleaner mix
you can get a 20ml test bottle of ar6200 and test next mot add to 2 tanks
tank before mot and tank for mot to be sure and see what result blows
sometimes you can pick up a free ar6200 with their injector cleaners like ar6400 or even a 20ml 5-8quid on its own.
only way you will know for sure is to test something.

 

[Zeewulf]

it doesn't go anywhere near the engine, as already stated it's injected into the exhaust system as the gas exits. If your car doesn't come with it as standard then you can't use it.

Wasn't you thinking of giving the engine the Terraclean procedure before your MOT ?

 

[sussexa]

topped up this morning my last bottle im using currently is ar6900

 

[Ralf S.]

Yes, I found out a bit more about it. It looks like the Adblu is injected into the exhuast header, after the fuel has been burnt, rather than being lobbed into the combustion chamber with the fuel, so obviously the car needs to have the gubbins for it.

It's a pity really... I thought I could just pee in the tank and reduce the car's emissions with my own..

At the moment Gerrard gets:

> A regular shot (5ml per tank) of 2-EHN, which is a cetane enhancer - theoretically allowing a better burn and hence less soot/smoke, although JTD might be too primitive to really make use of it.

> The same amount of kerosene now and again to remove any varnish/gum from the injection system.

> A dash of 2-stroke oil since too much 2-EHN doesn't like rubber, so the 2T oil will lubricate the diesel pump seals, if they needs it.

I also gave the beast a treatment of Cataclean in the Spring, so it may be worth another treatment, since that was 15,000 miles ago. Cataclean is basically a Propanol/Toluene/Acetone mixture... which is interesting since RedEx is essentially Kerosene/Toluene/Acetone. I need to get into some Toluene/Acetone and brew my own (I already have Kerosene and Propanol lying about... )

I tend to use the supermarket fuel most of the time, since Joe Sainsbury is 5p a litre cheaper than Esso/Shell where I live... but around MOT time I usually switch to the branded fuel to take advantage of any better burning/cleaning ability they have leading up to and during the annual dance with Dr Death, my MOT man.

At the moment the EGR lives either side of a pair of blanking plates so it stays clean but I guess at the expense of slightly higher NOx

I dunno what the EGR does to CO/2 so if anyone thinks the EGR lowers CO/2 then I'll un-blank it, at least for the MOT.

I will probably Terraclean the beast just before the MOT (and after I have un-blanked the EGR, if I need to).

It'll be interesting to see what difference all this makes to the emissions. Last year it was 1.46 when it just had to beat 1.50....whereas the new MOT says it has to beat "the plate" and "the plate" says 1.34.


Ralf S.

 

[Eklipze3k]

I dunno what the EGR does to CO/2 so if anyone thinks the EGR lowers CO/2 then I'll un-blank it, at least for the MOT.

With the changes to the MOT rules in May, this should be an MOT fail just for having it blanked.

 

[Ralf S.]

With the changes to the MOT rules in May, this should be an MOT fail just for having it blanked.

I thought that was just the DPF/particulate filter.

My old beast is Euro-III so never had a DPF. It also makes more "visble smoke" than a burning Kuwaiti oil field... whereas anything that has, or should have, a DPF would fail for smoke.


I do have one "secret weapon" in my arsenal... my MOT expires on 23rd December.. so I usually book it in with the Doctor in the last timeslot on the last day before he closes up for Christmas, when he just wants to get outta there..



Ralf S.

 

[Eklipze3k]

It is an offence under the Road vehicles (Construction and Use) Regulations (Regulation 61a(3))1 to use a vehicle which has been modified in such a way that it no longer complies with the air pollutant emissions standards it was designed to meet.

EGR counts here

 

[Ralf S.]

Aye okay..

I was going to re-boot it anyway. EGR was cleaned and it's been working okay (behind the blanking plates) since I dismantled it to clean it out about 18 months or so ago. It was badly coked up and giving me lot of errors until then, so the blank plates were really just to keep the error warning messages away..

The plates do also seem to be keeping the oil cleaner and the car is marginally more spritely and less sluggish.

The soot out of the exhaust seems to vary every week regardless of what I do. I try to boot it a bit in the same place every day (away from a particular junction and up a slight hill) to give the system a work-out. If I do that every day there's less soot. If I just plod around slowly for a whole week then it's worse, so some light exercise does seem to help..

Ralf S.

 

[Zeewulf]

Wouldn't the official Fiat part blanking plate be ok though, as it only allows a smaller amount through but at an increased speed. Plus it's an official update to reduce the flat spots, recommended by Fiat & Bosch ?

https://www.fiatforum.com/downloads.php?do=download&downloadid=548

 

[Ralf S.]

Hmm.... that's given me food for thought.

Rather than just remove the 2 plates I have (one at either end of the EGR), I might replace them with new ones with the holes in them... so I still get the EGR involved doing its thing but with better swirl/gas speed that the modified plates bring, to avoid getting back to the bad old days of sooted up EGR and error messages (although I think Gerrard's problems were brought about the previous owner over filling the oil (intake manifold, the inlet pipes and the boost valve were all full of 10W40 when I bought it).

The next job though is sort out a lazy hand-brake mechanism that sometimes doesn't let the pads go. Anything to do with the EGR will be a mid-December job, so it doesn't have too much time to soot up (if it will) before the MOT.

Ralf S.