How Do I Add DEF Fluid?

[weirdstuff]

Just hit about 9,000 miles and the DEF warning came on. It must be easy to add this stuff, right?

There's a Walmart somewhere around here, so we can go buy the stuff. How much do we need?

And, once we pop the hood, is it easy and obvious to figure out where to put it?

I don't even mind spending an extra $15 to pay Mercedes to do it for me, but it's just a time sucking hassle to get an appointment.

Thanks for your help!

[weirdstuff]

Also, meant to ask, what do we need to do at 10,000 miles? I remember some mention of 10,000 mile service.

[Protagonist]

Originally Posted by weirdstuff

Just hit about 9,000 miles and the DEF warning came on. It must be easy to add this stuff, right?

Yes. It's so easy even I can do it, and I'm not just all thumbs, I'm all toes!

There's a Walmart somewhere around here, so we can go buy the stuff. How much do we need?

I you get it at Walmart, it comes in a 2½-gallon container. That's just about the right amount, so you only need one.

And, once we pop the hood, is it easy and obvious to figure out where to put it?

Yes, it's obvious. Passenger side next to the radiator, there is a cap clearly labeled DEF, with an anti-spill gutter around it. That gutter is important. DEF will eat paint, so don't spill any!

I don't even mind spending an extra $15 to pay Mercedes to do it for me, but it's just a time sucking hassle to get an appointment.

You'd be paying a lot more than that at a Sprinter dealer! They sell DEF by the liter and you'd end up paying closer to $200 to get it done there by the time they add in labor.

10,000 mile service should be covered in your Sprinter Maintenance Manual. Just be sure that when you have the 10,000-mile service done, that you tell them you just added DEF less than 1000 miles previous, so they don't try to do it again and charge you for DEF you don't need.

[UKDUDE]

Regarding topping up with DEF, if you ask the Mercedes dealer to do it for you, you’ll probably end up with a bill for about $100 since they probably charge about $100 per hour labor, and an extortionate fee for their brand of DEF.

The DEF from Walmart is as good as any and much cheaper of course. Buy the 2.5 gal container because you will need as much to get the warning light off. And also because it includes a useful spout. DEF is corrosive, so be very careful and accurate when you’re filling it. It’s a little tricky since 2.5 gal is quite heavy.
The filler is under the hood on the left side as you’re facing it. It’s clearly marked.
Run the engine for a few minutes and the warning light will eventually go out.

Regarding service intervals, actually the vehicle computer will tell you when it needs a service. And recently there was a software upgrade that extended the interval even further. The interval depends on several factors including mileage and time. Buttons on the steering wheel will tell you how many miles to go for the next oil change.
Other maintenance checks will be done by the dealer at that time.

Actually you can download the Maintenance Manual here:
Mercedes-Benz Sprinter: Owners Manuals
Choose the one for your Sprinter manufacturing year - not the Airstream year. May be different.

[weirdstuff]

Thanks Protag and UKDUDE. I knew you guys would come through for me!

Protag, I seem to remember you posting a while back, that you add it at some mileage interval, even before your warning comes on. Can you please remind me what you do.

[Protagonist]

Originally Posted by weirdstuff

Protag, I seem to remember you posting a while back, that you add it at some mileage interval, even before your warning comes on.

You remember wrongly. It might have been some other guy who posted that.

I add DEF only when the dashboard warnings tell me to. The think is, as you've already discovered, the DEF interval is not the same as the maintenance interval.

[weirdstuff]

Originally Posted by Protagonist

You remember wrongly. It might have been some other guy who posted that.

I add DEF only when the dashboard warnings tell me to. The think is, as you've already discovered, the DEF interval is not the same as the maintenance interval.

Oh, sorry, I thought it was you. Someone said they add it every 5,000 miles, or something like that. Never mind!

[Protagonist]

Originally Posted by weirdstuff

Oh, sorry, I thought it was you. Someone said they add it every 5,000 miles, or something like that. Never mind!

De nada.

I never mind anyway. One must first have a mind in order to mind!

[weirdstuff]

Originally Posted by Protagonist

De nada.

I never mind anyway. One must first have a mind in order to mind!

haha!! Most people I know have lost their minds, so, I guess none of them mind either.

[David M]

If I recall correctly, the DEF tank holds 5 gallons. So if your DEF tank is completely empty, you might need to buy two 2.5 gallon containers at Walmart.

[Protagonist]

Originally Posted by David M

If I recall correctly, the DEF tank holds 5 gallons. So if your DEF tank is completely empty, you might need to buy two 2.5 gallon containers at Walmart.

The warning on the dashboard comes on long before the DEF tank is empty. And in fact if you don't fill it when it tells you to, you get a countdown clock:
"You have XX starts remaining"
and it will lock your ignition when XX reaches 0 so that you CAN'T start it, well before you run out of DEF.
You'll only need one 2½ gallon container of DEF at a time.

[73shark]

The DEF tank will last approximately 10,000 miles so if you go 'til the countdown starts, you can put almost ten gallons in. At least I did.

[UKDUDE]

Originally Posted by 73shark

The DEF tank will last approximately 10,000 miles so if you go 'til the countdown starts, you can put almost ten gallons in. At least I did.

Humm, the online manual states:

DEF supply reservoir content
Depending on equipment, the DEF supply reservoir content may vary.
Tank contents
Diesel Exhaust Fluid (DEF)13
Approx. 3.2 US gal (12.0 l)
Approx. 4.9 US gal (18.5 l)
Approx. 5.8 US gal (22.0 l)14

DEF consumption
Depending on the vehicle version, the DEF consumption is:
For the Cargo Van/Passenger Van, approximately 2322 MPG (0.10 l/100 km)
For the Cab Chassis, approximately 1720 MPG (0.14 l/100 km)

Notes:
13 DEF in accordance with ISO 22241. Observe the MB Specifications for Service Products, Sheet 352.0.
14 Cab Chassis only.

[David M]

UKDUDE, sounds right. 10,000 miles on 5 gallons of DEF.

[73shark]

I mispoke last nite. I meant five gallons. Darn CRS.

[weirdstuff]

We did it. Took both of us, but we did it. 5 gallons of DEF, in and done! Thanks for telling me it was so easy. Much cheaper and more convenient than taking her in to the "professionals."

[David M]

Congratulation! Glad it worked out.
David

[weirdstuff]

Originally Posted by David M

Congratulation! Glad it worked out.
David

Thanks! Celebrate the little accomplishments in life!