What is it with DEF?

[Gonzo42]

Just what is the Diesel Exhaust Fluid (DEF) ? What does it do and why do I need it? This is my first diesel and I never heard of it.

[Gonzo42]

Added to our profile:

MOTHER SHIP
Winneago View 24H (2007 Chassis, 2008 Body)3.0 L Diesel V6 bought used with 24K miles.

[ddschuman]

The Chevy dealership told us we only need to replace when the info panel says to. We buy it at SAMs Club and try to keep a spare jug on hand (use a jug, buy a jug sort of thing). Our last two trucks have required it. Once we needed it when we were traveling and bought at a truck stop. It is much less expensive at SAMs. It is for emissions control.

[Cummins12V98]

Gonzo42 wrote:
Then how would I know whether I am required to use it? I haven't seen anything in the manuals.

It would really help to fill in your visible profile. It would save a lot of guessing.

[VintageRacer]

5 seconds with Google taught me that the Sprinter went to a DPF - diesel particulate filter - in 2007 but did not go to DEF until 2010. So now you have to worry about what DPF is and what you need to do with it... 😉

Brian

[MTPockets1]

You'll find out if your truck needs it when you run out; your truck won't go. My message center gives me plenty of advance warning. 500 miles for first message. I get 5000 - 7000 miles between fills depending on how much towing is involved.

[Redsky]

Some of the new trucks have a gauge that tells you how much is in the tank which is a great feature. The DEF is injected into the exhaust stream and reduces particulate pollution by 99%.

There have been problems with the NOx sensors that tell the engine computer how much DEF to inject. If the sensors start to fail the DEF usage will jump and don't expect the engine codes to provide the correct information to the mechanic. Often the codes will state that the DEF is contaminated when it is simply a bad sensor giving bad information.

I fill up the tank before a trip and then get it as needed at truck stops at the pump and I take a very large funnel as the nozzles at the truck stops are meant for big rigs with saddle tanks and not the small filler spout in an engine compartment. GM's setup was definitely designed by monkeys and very stupid ones at that.

[navegator]

It Is not urine the chemical is "UREA"

As stated earlier do not use urine that is aprox 98% water, the chemical formula is(NH2)2CO

navegator

[hmknightnc]

Gonzo42 wrote:
Then how would I know whether I am required to use it? I haven't seen anything in the manuals.

It would be in your manuals and your truck would have a separate tank for the DEF. Tell us what truck you have and someone on here will know

edit- Just looked at your previous posts. A 2007 sprinter MB diesel probably doesn't use DEF but I am not sure. Somebody else will have to chime in.

[Gonzo42]

Then how would I know whether I am required to use it? I haven't seen anything in the manuals.

[Old-Biscuit]

Urea the active component of DEF has been in use for couple of hundred years. It is a organic compound in urine....but has been synthesized since 1922. Ain't enough cows to keep up with demand :B

Some of the other uses besides lowering NOx in diesel exhaust:

A stabilizer in nitrocellulose explosives
A component of animal feed, providing a relatively cheap source of nitrogen to promote growth
A non-corroding alternative to rock salt for road de-icing, and the hardening of ski-resort terrain park take-offs and landings
A flavor-enhancing additive for cigarettes
A main ingredient in hair removers such as Nair and Veet
A browning agent in factory-produced pretzels
An ingredient in some skin cream, moisturizers, hair conditioners
A reactant in some ready-to-use cold compresses for first-aid use, due to the endothermic reaction it creates when mixed with water
A cloud seeding agent, along with other salts
A flame-proofing agent, commonly used in dry chemical fire extinguisher charges such as the urea-potassium bicarbonate mixture
An ingredient in many tooth whitening products
An ingredient in dish soap
Along with ammonium phosphate, as a yeast nutrient, for fermentation of sugars into ethanol
A nutrient used by plankton in ocean nourishment experiments for geoengineering purposes
As an additive to extend the working temperature and open time of hide glue
As a solubility-enhancing and moisture-retaining additive to dye baths for textile dyeing or printing

Yep....folks have been eating it, smoking it, bathing with it, drinking it, primping with it, brushing with it, drinking it for decades.

We used to inject it into the burner flame pattern on commercial boilers to lower stack NOx emissions.
It was a new system.........proto type and I had to learn all about the stuff. Learned more than I cared to know.

[rtz549]

Get it at the pump for ~$2.79

http://www.pilotflyingj.com/def-at-the-pump

[jerem0621]

video

I like the way this guy from powerstroke help breaks this down.

Thanks!

Jeremiah

[hmknightnc]

Believe it or not it is basically urine (but don't piss in your tank). It treats the diesel exhaust to reduce pollution to meet EPA standards.

[Ol__Gold]

The way it came to the market by engine was based by how many engines the engine manufacturer produced. Ford was one of the first as they make few diesel engines by the numbers. (mostly for their pickup line.) Cummins was able to hold off as they made quite a number of engines. Think about the pickups as well as the over the road trucks. They are also big in the industrial line like marine, generators, well pumps etc. So in the big picture it was something that the federal government phased in by mandates. Engine manufacturers had to make a certain percentage of their production line meet the mandate. With that said, it is a far more efficient way of meeting the emission standard than some of the other ways that were previously used. It is by far a less power robbing way of doing the same thing.

Further, there are FleetPride truck part company's across the united states selling that DEF for around $10.00 or less per two gallon container. It does pay to shop the product. Don't spill it as its nasty when it dries.

[TucsonJim]

By "big rigs", I'm refering to commerical tractors such as Freight Liner, International, etc.