Outdated DEF?

[Camper Ken]

I bought my Mercedes Sprinter based motorhome last August and picked up a gallon of Valvoline DEF to keep with me when needed. The motorhome had about 1900 miles on it when delivered (from being driven from factory to west coast). The tech who did the walk through said he topped off the DEF. So far with just over 3,000 miles I haven't yet added any DEF, but I'm considering topping it off. Does DEF "go bad" or is it ok to use what I have? It's been stored in a cargo bay with temps between 30 - 90 degrees over the last 10 months.

[Old-Biscuit]

DEF will degrade over time depending on temperature and exposure to sun light. Expectations for shelf life as defined by ISO Spec 22241-3 are the minimum expectations for shelf life when stored at constant temperatures.
If stored between 10 and 90 deg F, shelf life will easily be one year.

[Camper Ken]

Originally Posted by Old-Biscuit

DEF will degrade over time depending on temperature and exposure to sun light. Expectations for shelf life as defined by ISO Spec 22241-3 are the minimum expectations for shelf life when stored at constant temperatures.
If stored between 10 and 90 deg F, shelf life will easily be one year.

Sounds like I should go ahead and use the DEF I have now. Thanks.

[S Bradley]

Originally Posted by Camper Ken

Sounds like I should go ahead and use the DEF I have now. Thanks.

Good question I guess I never gave it much thought.
If it hasn't been opened it is probably ok, check for crystals in the DEF.
It isn't that expensive if you're not comfortable using it, buy new.

I top off while on trips at 2000 and every time we are going to park for a few weeks, so mine never gets all that old. If you store it on board while driving it probably won't have any crystals because of the constant mixing.

[jackfish]

It might be better to just add DEF when prompted. No need to carry it with you as it is available almost anywhere.

[vsheetz]

I carry a jug of DEF with me, when refilling the tank it gets used first.

[Hooligan]

I'm of the other school. If it is a year old, toss it and replace with fresh, purchased when needed. The containers are dated so look for newer. It is used to clean/regenerate the Diesel Particulate Filter which is very $$$$ expensive if it clogs... 2.5 gl at Walmart is $10-15.

Chart by Ford indicated shelf life:
Below 50f (10c) 36 months
<77f (25c) 18 mos
<86f (30c) 12mos
<95f (35c) 6mos
<104f (40c) 2mos

[Steve Ownby]

Originally Posted by Hooligan

I'm of the other school. If it is a year old, toss it and replace with fresh, purchased when needed. The containers are dated so look for newer. It is used to clean/regenerate the Diesel Particulate Filter which is very $$$$ expensive if it clogs... 2.5 gl at Walmart is $10-15.

Chart by Ford indicated shelf life:
Below 50f (10c) 36 months
<77f (25c) 18 mos
<86f (30c) 12mos
<95f (35c) 6mos
<104f (40c) 2mos

The DEF is injected into the exhaust to reduce the NOX to a level below the EPA mandated threshold. The DPF is a filter which traps the particulates present in diesel combustion. The DPF does have to run through a regen cycle from time to time based on type of driving but this is accomplished by the injection of raw fuel into the filter. The DEF isn't part of this process. These two systems accomplish different things but both are part of the exhaust system.

[Hooligan]

Thanks Steve: I thought I read an article to that effect but I see now how it works.

[User1011]

Does anyone know if the DEF can be siphoned from the DEF tank on a MB Sprinter (2014 chassis) in order to re- fill the tank with fresh DEF ?

[lindenengine]

Originally Posted by 2LT

Does anyone know if the DEF can be siphoned from the DEF tank on a MB Sprinter (2014 chassis) in order to re- fill the tank with fresh DEF ?

Yes it can.
Dennis

[Kern]

Originally Posted by 2LT

Does anyone know if the DEF can be siphoned from the DEF tank on a MB Sprinter (2014 chassis) in order to re- fill the tank with fresh DEF ?

I agree with Dennis. You can drain your DEF storage tank by siphoning. DEF is a very simple solution of about 32.5% urea and 67.5% distilled water (no minerals). Urea is (obviously) a water soluble nitrogen (47%) containing organic compound. The waste DEF fluid can be safely disposed of by highly diluting it with water and spraying it on your lawn. It will green up your lawn nicely. I'd use one of those jars that attaches to the end of the hose so that you can dilute and spray it that way. Water your lawn right after spraying to soak it in.

Kern
Pleasure Way
2014 Plateau TS

[User1011]

Originally Posted by Kern

I agree with Dennis. You can drain your DEF storage tank by siphoning. DEF is a very simple solution of about 32.5% urea and 67.5% distilled water (no minerals). Urea is (obviously) a water soluble nitrogen (47%) containing organic compound. The waste DEF fluid can be safely disposed of by highly diluting it with water and spraying it on your lawn. It will green up your lawn nicely. I'd use one of those jars that attaches to the end of the hose so that you can dilute and spray it that way. Water your lawn right after spraying to soak it in.

Kern
Pleasure Way
2014 Plateau TS

Thank you, Kern, and thank you Dennis -- however, not concerned about the DEF --- well aware of the composition.

The issue is that we tried to siphon and met resistance with the tubing not advancing so therefore aborted the attempt. So I'm assuming that the tubing we used was too firm and there must be an angle of some degree that the tubing was not flexible enough to move through the fill line area to the tank itself? Any suggestions on what kind of tubing can be used successfully ?

[Kern]

I'd use the softest vinyl tubing you can buy. Lowes has it. Maybe you should snake it along from the outside of the fill cap to the bottom of the tank and make a mark at the fill cap. That way you can follow the progress of the tubing into the tank. I'd be leery about forcing this into the tank. The tank has some kind of volume sensor so you don't want to push this around with the hose. The MB computer is going to give you a weird message if you whack the sensor too hard. Go with thin wall 1/4 inch tubing. It should bend when pushed against any obstruction.

Alternatively, maybe there is a drain valve at the bottom of the tank. Have you crawled under the rig to see?