Hi Im looking at getting a new f350 4x4 a 17 or 18
my question is I'll be driving it maybe 4000miles a year what problem will I have with the def fluid sitting in the truck for long time and not driving much thanks

 

You should have no problems with the DEF. I have only put 2500 miles on my 2015 in the last year with no problems during recent drives. The last "drive" I made was 200 miles each way last week with no problems.

 

just don't fill it till it is called for. You the ford spout to refill so you don't over do it.

 

DEF has a shelf life of around 24 months, depending on how it is stored. Manufacturers recommend a cool, dark location for storage. The DEF tank on your truck qualifies as dark but not always cool.

I put about 6,000 miles on my truck a year. I use a lot more DEF than others because most of those miles are towing in the Rocky Mountains. I've added 5 gallons of DEF to my truck and the tank is sitting at a bit above half full. I add a 2.5 gallon jug when the tank gets below half full.

DEF freezes at 12 degrees. There is a heater in your DEF tank to keep the DEF a liquid while the engine is running. DEF expands 7% when frozen. So don't overfill the tank when freezing is possible.

 

Not aware of DEF having a shelf life. I have used DEF that I carried in the tool box of the truck for 3 years with no problems. There is not a use by or best by date on DEF.

 

From the PDF linked below:
http://www.sboil.com/cms/wp-content/...Sheet-0112.pdf

 

The shelf life of DEF is directly related to the temperature at which it is stored. Storage temperature between 12º and 86º F are recommended to maintain optimal shelf life of up to two years. If BlueDEF freezes, its efficacy will not be effected upon thawing.

This is a company brochure to promote their product and sell more. Do you honestly think bulk DEF is kept at optimal temps and stored in sealed containers?

You can buy yours as you want. I have not had any problems using DEF that was older and sealed prior to use.

 

The brochure is saying the same thing I found on a number of other web sites. Some sites were more pessimistic and suggested a shelf life of around 12 months.

The bulk DEF - at least the product purchased at truck stops - is stored underground. A dark, cool location. Plus, they likely turn around their product fairly quick.

 

thanks for all the info guys I just heard bad things if it sat too Long so now I have to fork out the 65k for a new truck i hate to get rid of my 7.3 but it really doesn't like 17k of a trailer and California is cracking down on people hauling trailers that are too heavy for their trucks

 

Here is what Ford has to say on the matter.

"Unless there is a warning light on the instrument panel there is no reason to consider draining the DEF from the tank simply due to age of the DEF."

 

Hey all, just had this issue and wanted to pass along my solution, which did not require going to the mechanic. The backstory: My truck is a 2015 F-350 Lariat. I topped off the DEF while at a pump that had it and the warning was not on, not realizing that would be a problem, then got the warning a few thousand miles later when towing my 5th wheel on the other damn side of the country. Bought some DEF, topped it off again with about 2 gallons, warning did not go away. Called a nearby Ford dealer, they said they wouldn't be able to get me in for 3 weeks because COVID or something, and I needed to head back within a week. And I didn't want to have to do 50mph back across the country, so I considered my options.

One redneck approach I considered was to go to the hardware store and buy some tubing and siphon out the DEF, let it put me in limp mode, then add more back to it. I suppose that could have worked, but then I remembered that I had FORscan...

With a $18 OBD-USB adapter that I already had for doing manual DPF regens with the FORscan software on my laptop, I plugged it in and took a look at what my options were in FORscan. Sure enough, there is a service procedure you can do with it (even with the free version!) called "SCR System Refill Activation" - sounded like the one I needed, since DEF is for the SCR system, and this is about telling the system it is refilled... sure enough, a few minutes later, and it was fixed. No trip to the mechanic necessary. Just make sure you do it with a full DEF tank so it gets in sync. I am pretty sure this is all a dealer/mechanic would do anyways.

I highly recommend all 6.7L owners have this adapter on hand. Not only has it paid for itself with doing manual DPF regens, but this saved my bacon with this procedure. I drove the few-thousand-mile trip back without issue. Search "FORScan OBD" in Amazon and get one that has an HS/MS switch. The one I used was about $18. Far cheaper than a trip to the shop. I have since bought a FORscan license, even though I only needed the free functionality, to thank the awesome team making this software.

(Regarding manual DPF regens, offtopic: my truck's automatic regens don't seem to work properly, and I got put in limp mode once because it got clogged. My truck does not have the operator-controlled regen feature. And before you suggest I use my F-350 as a grocery getter and just need to work it harder, I mostly only use it for towing a 7-ton trailer which causes high RPMs, and this happened after several hours on the highway towing when it was working hard, and all the while saying it was automatically cleaning. Mechanic charged me ~$60 to do a manual regen. So I now do that myself every 6 months, and the $18 adapter paid for itself the first time I used it.)

 

Ill have to investigate that

 

Peak has some new fancy Platinum version of DEF, supposed to keep deposits and stuff in check and what not, whether it works or not, I don't know. However if I only put a few miles on my truck per year it's what I would use