DEF fluid sub distilled H2O

Talking with mechanic for state owned trucks today. Had barrel of DEF had to move. He stated someone had used distilled water in a pinch with no problem. We wondered if it could be used all the time. He was not about to experiment with state owned trucks.Anybody else heard of this? Just where is the DEF fluid injected . Someone said in exhaust, but this sounds to easy! Could it be cut so to speak with water?

It is 32% nitrogen and water. Some dummies are getting the tanks switched and putting DEF in the diesel tank and diesel in the DEF tank. Diesels do not run well on water.

The DEF is injected into the exhaust system and reacts with the NOX to break it into nitrogen gas and water vapor. It works entirely "downstream" of the engine.

All Tier IV engines have NOX sensors in the exhaust system to make sure the system is working per the EPA regulations. If a person tried to use just water or even diluted DEF in place of the full strength DEF the sensors would detect the increased NOX and would derate the engine. In addition, the use of a DEF quality sensor in the tank is also being pushed by the EPA which would trip the derate system even before the exhaust stream sensors detected anything.

I've also heard of guys mistakenly putting diesel into the DEF tank. This is very bad because it will quickly damage some very expensive components in the exhaust system.

if its 32 per cent nitrogen and water wonder if comnon farm fertlizer would work?

I have a new Tier IV emission tractor ( brought in April kubota L4600) it does not have all that junk on it... I was told it was the last one in captivity he may have been right all the other Tier IV I have seen have the full Tier IV emissions...

The exhaust components you'd be risking damage to cost thousands of dollars (literally) and the OEM's warranty department would have no forgiveness. DEF is much more highly purified and filtered than liquid fertilizer. Is it really worth the risk?

How will water will increase NOx...

I know you are joking but this is no joke you will be trained to use DEF and will learn to love it...

A couple times now I have run out and gotten de-rated. Just poured my gallon of drinking water in the tank and drove to the next fuel stop and filled up. No problems so far. Lot's of truckers have done it and I have not heard of any problems from it. I don't run it long tho and fill the tank to dilute it as soon as possible.

That would take care of the level alarm, but you would get a NOx alarm.

It is a refined Urea.

Well, you _could_ always Pee in the DEF tank. After all, DEF is just synthetic pee.

Hi that DEF is so sensitive, a tea spoon of copper filings will destroy a 1000 liter tote.

I got one farm customer just paid a $1000 to New Holland, as he rented a tractor and put Coop fluid in it. It shut the system down as it only liked NH fluid.
Don't mess with anything other than DEF, and even if that gets contaminated it can cost thousands to fix sensors and stuff. Heard of a muffler was $5000, a month out of warranty.
How much DEF can you buy in that cost over the saving on cost cutting.
I got a feeling in 5 years this system parts will be obsolete and then you will be forced to buy the latest equipment with the next generation more stupid emissions junk than the garbage is now.
Regards Robert

How about putting windshield washer being put in because the cap under the hood is blue. Heard that from one customer.

Never got one of those alarms.

I think someone is not telling the whole story on the new holland deal. If he used DEF then it's not his fault. If he got bad DEF from the coop then they should pay.

I work for a very large truck leasing company.The scr (def and dpf combined) system is an industry nightmare.There are well over 1000 engine/emission fault codes that can arise on any modern truck, not counting the cab,abs, or trans ecms.The systems are very complex; even how the truck is driven has a bearing on the scr system(light load vs. heavy; stop&go vs.long haul). Diagnostics is very time consuming; you have nox codes:you have to test the purity of the def,there is inlet and outlet readings to compare,there is pressure and quanity tests to perform. There are problems with the pumps, the sensors and the ecms. Ecms have to be upgraded constantly to have the latest software installed as engineers replot operating parameters and strategies.Qualified techs are becoming scarce and tech support is overrun with problems.
Jon f mn., I am very surprised you get away with distilled water; if you own that truck, carry a tote of def in your side box, you do not want to pay to have it fixed$$$.
Also, what Bendon-Ks says is accurate, how the scr,(supplemental catalyst reduction)works.
At our shop,at least 1 of 5 techs, sometimes 2 or 3, is almost always working on a truck with fault codes and many are scr,dpf related. The driver is part of the emissions system and has to 'obey' the warning lights=regen needed,def low,etc., or the truck will derate,in some cases 5 mph top speed, and have to be towed. 1 model, customers are bad about putting diesel in the def tank: then the tank has to be removed and cleaned ,lines flushed out,if run long enough, the nox sensors need replaced. Very expensive bill for customer$$$.
I believe this emissions stuff is needed,oems would try to prove to epa if it was not.It's worldwide. It costs lots of $$$ to engineer,it costs lots to repair. The customer/consumer has to pay higher prices. Is it the best solution- I don't know-is something better coming - time will tell.Mark

Hi
I was there at the customers when it was being talked about by him. and that is all I can tell you so Don"t Know any more than that sadly.

I have heard that there is something in fluid so you can"t make your own and run it. so don"t see why the nice guys at NH couldn"t goof with the potion so you have to run theirs?.
Will eventually here from guys if it"s happening more or whether it was a bad batch.
Regards Robert

No, you can't use water or pee. Def is 33% urea 66% deionized water. The urea breaks down in the heat of the exhaust to release ammonia. The ammonia reacts in the selective catalyst reduction section of the exhaust to convert NOX to nitrogen and water. You might be able to fool the low level warning with water, but eventually the system is going to detect elevated NOX levels and eventually derate speed.
DEF fluid in the fuel tank is certain death to the fuel system. It's very corrosive to metal. One speck of rust is enough to stick an injector open or closed.
Probably why they have a barrel of Def to get rid of is it's a perishable product. Stored over 90 degrees can cause it to degrade to the point it no longer controls NOX.