that video is from 2010....I think all DEF trucks have sensors to prevent that now.

 

It 100% has a sensor and goes into LIMP mode without DEF. Even bad DEF can cause an issue. DEF is pretty darn cheap considering everything else.

 

Try it for us

 

We got feed grade urea sitting around (basically the same as fertilizer plants) in dry form. One day we were looking at the ingredients on a def jug and grabbed some urea and distilled water and mixed them up. The urea dissolved perfectly, but i wasn't brave enough to dump it in the tank.

We have a cab and chassis that may get cleaned up so I could try it there and if it messes it up I guess it is coming off any ways.

 

You spend $50K or more on a highly refined diesel and now you want to save a few bucks on DEF. Really. There are sensors in the DEF system that will cost you big bucks and when the system goes south the dealer will test your DEF. Better hope it tests good. My advice is buy good quality DEF in sealed containers or a reliable truck stop diesel island. You will pay to play with it.

 

You spend $50K or more on a highly refined diesel and now you want to save a few bucks on DEF. Really.

Not at all.
- I do have money to burn, but I'm aware of the def quality sensor in the Newer Trucks that would foil the attempt.

question part duex.
The question is: (Now Modified for those who didn't draw the conclusion the first time)

With the absence of the def quality sensors....Would the engine run as normal if you ran water instead of def fluid?

I believe it would, as that appears to be the reason for adding the Newer Quality sensor. To avert what the truckers discovered way back in 2010.
- I bet if you tried it in the first year models of def truck it would work. Trucks that did not have the sensor.

discuss.

 

Well, all of the questions about why you might want to do this aside...

DEF is mostly water. The SCR emissions system is almost entirely high grade stainless steel. Urea is corrosive. If you remove the urea from the DEF -- that is, if you run water through the injectors instead -- it probably won't hurt anything, since you're reducing the level and quantity of corrosive reactants inside the stainless steel SCR system. Since that reaction is exothermic -- SCR systems get hot -- you'll also reduce physical wear and tear on the system from thermal cycling. You might also build up crud inside the reaction chamber different from the crud it's designed to handle. I'm not sure about that.

That having been said, you're also removing the catalyst from the Selective Catalytic Reduction emissions system, which means you'll get no reactions inside the chamber, and no subsequent reduction of NOx.

If you run out of DEF entirely your truck will fall into limp home mode because it knows there's nothing running through the injectors.

I really doubt that the system pre-tests for a urea solute in the DEF injectors. However, the system absolutely tests for NOx reduction after the reaction chamber. The whole point of SCR is near-zero NOx emissions from a diesel.... so you know those sensors are going to be picky. If they pick up LOADS of NOx, you're going to throw really big emissions codes. I don't know if that will throw you into limp mode or not.

We also know that the DEF system is finicky. Overfill it... let it get too low... and member trucks have gone into limp home mode. That means a dealer visit.

So... it seems like a hugely negative set of outcomes for... let me estimate... a less than 2% reduction in fuel costs?

 

Don't you think the manufacturers would gladly have you use water instead of DEF if it was possible? Isn't the emissions tested after the SCR catalyst? I doubt water alone will sufficiently reduce NOX levels.

 

I don't know for sure - but I do know that California does what is called a Snap Throttle Test - used to Smog Diesel Trucks. ( It's not a actual measurement of Nox. )

It's a visual test after mashing the throttle. They wait to see how long it takes for the black smoke to dissipate.
Seems crazy I know - especially for a crazy state like Ca that goes a long way to jam regulations down your throat.
No actual measurement.

 

Diesel smog check are required for all diesel vehicles that are 1998 or newer.
- That rule was enacted in 2010. Ca. decided to go back a few years and give those guys grief.
All 14,000 GVWR and Under.

 

I wonder how the 1998 Cummins 12v pass the smoke test? They smoked from brand new under full throttle. My guess is it's one of the reasons they went to the 24v mid year.

 

Is the snap throttle check for emission or pre-emission trucks?

 

Snap throttle is alive and well. If it smokes, it fails.
Take my word for it. I'm the guy doing the testing >

 

So,, is it possible to get a "modified" truck to pass smog or at least get the cert in Calif? Yes, I know it's not legal but people to a lot of stuff that's not legal. Mine is all legal. I have been told that it is possible to delete and get a cert with a few extra $$$. Not going to do that but just curious about the underworld. Since you test, does the gov't go after modified diesels? Unlike many of the Federal laws, smog is one that Calif really follows.

 

AFAIK, in Calif if it isn't like it came from the factory, tune and all, it fails. No matter how clean it's running.