DEF Tanks?

[jage]

Just saw this pic of a 2011 GM van:



And since I'm not up on the latest Diesel engines here's my understanding:
1. It's concentrated urea* that you buy in a jug a la antifreeze
2. You fill your own at every oil change
3. It's injected downstream in the exhaust to eliminate NOx**
4. If you get low you get a warning (hate your seatbelt chime? that's nothing...)
5. If you run out you go into limp mode (been there on the 6.0L, no fun...)

That's all I know, and it comes in the form of "NEWS TO ME". Here's my main source:
http://www.duramaxforum.com/forum/gener ... -uses.html

So, surprised it hasn't come up more in discussion yet. My questions:

* what's that do to paint?
** this is basically anit-smog right?

And last but not least, Sprinter is offering an underhood smaller tank, which is where I heard about it in the first place:
viewtopic.php?f=4&t=7360&hilit=DEF

For someone with their head in the sand... wow! um, just wow.

[WVvan]

Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals.

So if you ever get the "low-fluid" warning in the DEF tank it shouldn't be be too hard to refill it right?

[BroncoHauler]

Originally Posted by WVvan

So if you ever get the "low-fluid" warning in the DEF tank it shouldn't be be too hard to refill it right?

The end to pit-stops as we know it. Nothing stopping me from driving 600 miles non-stop now!


Herb

[daveb]

We have had em on our new Fords at work for about a year. The engine does not sound like a diesel. Good point if you think the 6.0 was noisy but they kind of sound like a industrial sewing machine now. I think our trucks have to go through CHP check every 2 months (???) but in between we put a gob of miles on them and they typically idle while not on the road for the 8 hr shift. The shop puts the stuff in during the CHP inspection and it has never seemed to go dry. Don't know much more than that.

[jage]

Originally Posted by WVvan

So if you ever get the "low-fluid" warning in the DEF tank it shouldn't be be too hard to refill it right?

Along those lines... how does, or does the vehicle know you're not just adding, say, water?

[webbmac]

Originally Posted by jage

Along those lines... how does, or does the vehicle know you're not just adding, say, water?

Or 'urea'?

[carringb]

Diesel Exhaust Fluid, which is urea, allows diesel engines to burn hotter, without exceeding NOx limits at the tailpipe. This is actually good, because it reduces particulates. Starting in '08, requirements for particulates emissions became really stringent, so diesels got these particulate traps in the exhaust. These fill up, so the PCM activates a "regen" mode to burn the stuff out. Problem is... regen mode uses lots of fuel, and can also dilute oil. By burning hotter, far less particulates are collected in the trap, and therefore regen mode becomes much less frequent.

There's other methods to reducing NOx. Dodge uses an absorber catalyst combined with more EGR flow. This means Dodge diesels don't need Urea. But they use about 10-15% more fuel than the new GM and Ford diesels which use urea.

The trucks have sensors to detect if the proper concentration of urea was put in the tank.

If you keep ignoring the empty warning, the vehicle will eventually allow nothing more than an idle.

The DEF tank have a heater which heats the tank when the truck is running. The PCM won't call for any until it has thawed out.

I think it would be prudent to wash of any spilled urea.

[witoke]

The urea is injected into the exhaust stream from the tank where it decreases NOx. It's not mixed with fuel for combustion, at least in small vehicles.

The following article gives a bit more detail:

http://www.businessinsider.com/adding-u ... ank-2011-6

[Silver350]

Originally Posted by jage

Along those lines... how does, or does the vehicle know you're not just adding, say, water?

It's not any harder than re filling your windshield juice. Unless you are buying it in drums, it will cost more than Diesel.