What is it with DEF?

The def tank has a heater. When below a certain temp the ecu knows the def is frozen and it alllows the truck to run without it for a certain amount of time so as for it to thaw.

aruba5er wrote:
I would not buy some to keep on hand. It's too avaiable and it has a made on date (code) but they want you to keep it fresh. My 2011 dura max has been back 3 times for trouble. Last time I bought some from a pump and shortly thereafter message said poor quality See instruction book. You can not drain the tank, it must be pumped out. GM dealer did all the things the co. required and they reset the computer and in a couple weeks it happened again. This time with fresh GM DEF. so far no more trouble. BUT how does it work when the stuff is FROZEN SOLID?

We had a 2011 prior to our current truck. There were lots of bugs with the 2011. Our truck was in he shop more than it was out. They finally replaced the entire tank and assembly and the problems went away. DH had to be towed twice before they took this action. We have had no problems with the our 2012 and have had it going on 2 years. We do keep DEF on hand but not like it may sound. The closest SAMs store is about 50 miles from home. We only go about every other month. Owning a HVAC business in a very rural area, DH does a lot of driving. He may replace the DEF one month and go to SAMs the next. It doesn't sit more than about a month maybe slightly longer before being used. We've had no issues thus far.

rtz549 wrote:
Get it at the pump for ~$2.79

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

Much written on here about the subject - problem at buying at the pump is that most of us have the fill on the passenger side of the MH and pumps are on the driver side - including all Flying J that I have seen

I would not buy some to keep on hand. It's too avaiable and it has a made on date (code) but they want you to keep it fresh. My 2011 dura max has been back 3 times for trouble. Last time I bought some from a pump and shortly thereafter message said poor quality See instruction book. You can not drain the tank, it must be pumped out. GM dealer did all the things the co. required and they reset the computer and in a couple weeks it happened again. This time with fresh GM DEF. so far no more trouble. BUT how does it work when the stuff is FROZEN SOLID?

Added to our profile:

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

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.

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.

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

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.

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.