Has anyone actually looked under one of the 2011s at an auto show, or via privileged access, to see where the urea injection point is in the exhaust line? The theoretical arrangement, based on internet descriptions of the process, could put it between the DPF and muffler (i.e. a final stage in the emissions system) or between the DOC and the DPF.

Has anyone actually looked under one of the 2011s at an auto show, or via privileged access, to see where the urea injection point is in the exhaust line? The theoretical arrangement, based on internet descriptions of the process, could put it between the DPF and muffler (i.e. a final stage in the emissions system) or between the DOC and the DPF.

that may be the injector right after the CAT


Meets Tougher Emissions
http://blogs.cars.com/.a/6a00d83451b3c669e201287783b258970c-800wi
Like Ford's Power Stroke, the Duramax will use selective catalytic reduction, or SCR, and a new high-capacity two-stage exhaust gas recirculation system to scrub nitrogen oxide emissions down to no more than 0.2 grams per horsepower/hour. It's a new EPA requirement as of Jan. 1.
The SCR system uses diesel exhaust fluid, or DEF. The urea-based solution (32.5 percent industrial urea and 67.5 percent deionized water) is held in a 5.3-gallon storage tank and injected as a fine mist into the Duramax’s hot exhaust gases. The heat turns the urea into ammonia that, when combined with a special catalytic converter, breaks down the nitrogen oxide emissions into harmless nitrogen gas and water vapor.
The 2010 Ram Heavy Duty 2500 and 3500 pickup trucks with the 6.7-liter Cummins I-6 diesel don't require DEF. They use a scrubbing solution called an adsorber catalyst that uses precious metals like a catalytic converter to eliminate the pollutant. However, the Ram 3500/4500/5500 commercial cab chassis trucks do use SCR, like GM and Ford.
The DEF refill point for the Silverado HD is mounted under the hood of the engine instead of next to the diesel refueling cap on the side of the cargo box, as it is on the 2011 Super Duty.
Arvan said DEF will need to be replenished about every 5,000 miles, depending on duty cycle. An electric heating element inside the tank will thaw the fluid if it freezes.
"We didn't want to make the DEF tank larger because DEF has a shelf life of only about 12 months," Arvan said.
To ensure that the driver refills the DEF tank, Duramax-equipped trucks will warn the driver when the fluid is down to a 1,000-mile range. A series of start-up warnings — including lights, chimes and messages — will become more frequent until the tank is empty. When the DEF fluid is down to a 100-mile range, the truck will be limited to only 55 mph. As the range declines, so will the vehicle's top speed. If the driver continues to operate the truck with a dry DEF tank, after a final warning and restart, the truck will operate in a “limp home” mode that limits speed to just 5 mph until the tank is refilled.
While some may not like having to deal with another maintenance item like DEF, the SCR system in one enabler in helping the Duramax return better mileage than its predecessor.

Yup, that sure looks like it is right after the DOC catalyst, thanks.

Yup, that sure looks like it is right after the DOC catalyst, thanks.

Any time:).......I would hate to see the repair bill when that b/s goes bad:eek:

Does anyone know how this system works? Is it a continuous stream that is injected at a super low amount, or is the urea only injected at the time of a regen?

yea, thats not a 5.5 gallon tank...

All of the material I've read on it so far indicates that the urea has to be injected continuously. The amount being injected is controlled by the onboard computer, depending on a host of factors that affect the likely amount of oxides of nitrogen in the exhaust. For example, engine load, vehicle speed, exhaust temperature, etc. I'll find a link to a basic explanation and post it here soon.

Here are two fairly basic explanations:
http://alternativefuels.about.com/od/researchdevelopment/a/scr.htm (http://alternativefuels.about.com/od/researchdevelopment/a/scr.htm)
and
http://www.afdc.energy.gov/afdc/vehicles/diesels_catalytic.html (http://www.afdc.energy.gov/afdc/vehicles/diesels_catalytic.html)
Here is a more complex discussion, complete with chemical reactions:
http://en.wikipedia.org/wiki/Selective_catalytic_reduction (http://en.wikipedia.org/wiki/Selective_catalytic_reduction)

Any time:).......I would hate to see the repair bill when that b/s goes bad:eek:


The repair bill wont be any more than your bill was with me to fix your cracked dpf issue :) Breakdown of cost: Sawzall $165, Demolition blade $5, band clamps $8, stainless pipe $125, use of the mandrel bender $20 :) See what I am getting at?

So what if you just run it out of fluid? Will the truck not run anymore or is there something else to this?

Also - I wonder how bad that stuff would smell in the tank. Think about it. Reminds me of a radiator in a men's restroom... You know what I am all talking about. :)

The repair bill wont be any more than your bill was with me to fix your cracked dpf issue :) Breakdown of cost: Sawzall $165, Demolition blade $5, band clamps $8, stainless pipe $125, use of the mandrel bender $20 :) See what I am getting at?

So what if you just run it out of fluid? Will the truck not run anymore or is there something else to this?

Also - I wonder how bad that stuff would smell in the tank. Think about it. Reminds me of a radiator in a men's restroom... You know what I am all talking about. :)

Stop buying cheap tools):h):h........ and at least I paied you..... dammit:stick_out


You aint got nothing better to do but troll were ever i go:shake: :p:

The repair bill wont be any more than your bill was with me to fix your cracked dpf issue :) Breakdown of cost: Sawzall $165, Demolition blade $5, band clamps $8, stainless pipe $125, use of the mandrel bender $20 :) See what I am getting at?

So what if you just run it out of fluid? Will the truck not run anymore or is there something else to this?

Also - I wonder how bad that stuff would smell in the tank. Think about it. Reminds me of a radiator in a men's restroom... You know what I am all talking about. :)
I work at a GMC dealership and they just said that it will go into limp mode if you run it out. It is going to give you a warning light and about 1000 miles head start to refill the tank.

What happens if we just fill it with deionozed water? ;)

What happens if we just fill it with deionozed water? ;)
Would that make it a steam engine and then not have any pollution rules?:cool:

Filling with de-ionized water only would not work because the NOX detector in the exhaust stream will recognise that no NOX conversion is taking place. It would probably first try increasing the injection rate, because it would assume that more urea is needed, and would then put the truck into limp mode.

I wonder how many thought of urinating in the tank...

I wonder how many thought of urinating in the tank...

and that would be time number 292195089896 that joke has been used.

And it just gets funnier each time!!!!!!!!!!!!!!!!!!!!

ben

im sure the system will be able to be disabled via the ecm

I was wondering what the range was of the urea tank under normal use. It is assumed that the tank will be filled at each oil change. Is that 5000km or an oil change based on the DIC on a Chev or GM.

Will urea consumption be far higher in Mexico requiring carrying some spare urea or are the nitrous oxides not affected by higher sulfur content in the diesel?

it will be able to go a little over 5,000 MILES, not kilometers on a tankful of urea. ;)

Pee in the tank :P
Urea=pee lol

I wonder how many thought of urinating in the tank...

Damn beat me too it lol :P

wow that sounds sick

Does anyone know how this system works? Is it a continuous stream that is injected at a super low amount, or is the urea only injected at the time of a regen?
it is only used in place of late post injections before the doc and the dpf

just another note the exh fluid is about $16 a gallon

just another note the exh fluid is about $16 a gallon

yeah maybe NOW it is. Check back in 3 months, I think you'll be surprised. ;)

Pour some gasoline in that tank then mash on the throttle. See if you can make your truck look like the Bat-Mobile!!!!

just another note the exh fluid is about $16 a gallon

Geez where do you shop? Beverly Hills Diesel:rolleyes:

DEF is barely on the market, and can be easily had at $5/gal, 2.5 gallon jug for $12.41
here's a link:
http://www.electotronics.com/terracairdef002525gallonultrapuredieselexhaustflui d.aspx

This stuff will be in your local autoparts store by the end of the year and will be less than $5/ gal.

Here's another link explaing DEF to those who refuse to get educated about it. The more people learn about it the more they will like it.
http://www.bigtrucktv.com/item.aspx?david_siler_2010_scr