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Running out of diesel exhaust fluid DEF

208K views 62 replies 43 participants last post by  dalestempel 
#1 ·
There is a question in this post, please bear with me or just scroll to the end.

I purchased a new F250 diesel and the instructions from the sales department was - don't worry about the DEF, we will take care of it every time you change your oil and it will never be an issue. So what really happens when your dealer does not add diesel exhaust fluid during the oil change and you run out? Here is my experience:

With about 7000 miles on the odometer I was leaving for 1000 mile round trip weekend event in which I had no extra time when dealerships are open. 50 miles in, the notice came one that diesel exhaust fluid is going to run out in 900 miles and the engine speed will be limited. Plenty of notice if it was not this specific weekend. During the event I had my brother run to a chicago ford dealer for DEF, they would not sell any as they only had 55 gallon drums. On Sunday, heading back to Minneapolis, out comes all the owners manuals and it seems that it should be an easy answer, get some DEF at most Truck Stops. The manual notes the engine management notice may not go off right away as it takes time to reset. The second truck stop we tried in Madison had DEF, $12.50 for 2-1/2 gallons. I put 2-1/2 gallons in the DEF fill tank, it was very easy and expected all things to go well. We are back on the road now and nothing happens, the notice that vehicle speed will be limited in XX miles keeps counting down. At first we were OK since the manual mentions it takes time to reset. We are now driving off interstate to pick up the dogs and nowhere near anything. Ford assistance lines on the phone have no help except sending gas or a tow truck if it is not 9-5 on a weekday. We get to a friends house with the countdown to limited vehicle speed at 15 miles.

After an unplanned overnight stay, we go to Wisconsin Rapids Ford. They were extremely helpful and I was able to talk to the technician even before the dealership opened. The technician was unsure about why the countdown did not reset, checked a few things and then decided to add more DEF. A little over 2-1/2 gallons topped it off and after turning the key, the countdown was turned off in about 2 seconds.

After checking in with my dealer in Minneapolis and confirming that they did not add DEF during my 5000 mile oil change I asked them to get some answers for me, I have not heard back from them in a month so here are the questions passed along to the forum.

1. Is the DEF sensor in my truck working properly or not? Does the DEF really need to be topped off to reset.

2. If the DEF sensor in my truck is not broken, certainly the owners manuals do not address this issue adequatly. Will they pass along a note to Ford to insert a DEF notice into the owners manuals so this does not happen to others?

3.If it does need to be topped off, what is the method to guage what the DEF level is rather than filling to spillover?


BTW, still loving the truck, pulls like a dream, almost double the gas mileage of my Tundra when towing the same trailer.
 
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#2 ·
The sensor in the DEF tank is not like your fuel gauge. It measures at certain increments, not a continual level sensing as with a fuel tank gauge system. It would be possible to add DEF and the next level in the gauge system to not be reached so it continues its threats and warnings. Adding the other 2.5 gallons certainly would go to the next increment and it registered the addition and all is good. Probably still worth a check the next time it gets in for service at you derelict home dealer
 
#3 ·
We just wrapped up 6500 mi on the new truck. At the first DEF warning, I added a gallon, thinking it was enough, no change in the warning, then I added another two, filling the tank, and that turned the warning off, so I would expect when the warning appears, it's is necessary to fill the tank to deactivate it.
Not an issue, so long as it is consistent
 
#5 ·
As 6.7psd said, You have to fill it PAST the half way point for it to reset. It's a 5.x gallon tank so 2.5 gallons is just not quite enough when you are empty.

The Ford DEF Bottle prevents you from overfilling and spilling out. Not only is this good for the paint, But in cold weather prevents DEF from freezing in the inlet tubing. The DEF tank has a heater to thaw and prevent freezing the inlet line does not. DON'T over fill in cold weather.

Depending on how you drive, A full tank of DEF may not last between oil changes. If you oil minder is going off at 7500 miles and your DEF is lasting 5000-6000 miles per tank. When ever mine gets below 1/2 tank, I add 2.5 gallons.
 
#6 ·
I just don't let my local dealer perform any remedial tasks simply because I can not trust them to do something this simple.
I just every once in a while check the System Check->Exhaust Fluid and if it says less than 1/2 then I'll make a note and stop by O'Reilleys and grab a 2 1/2 jug and fill it up.
 
#7 ·
...After checking in with my dealer in Minneapolis and confirming that they did not add DEF during my 5000 mile oil change I asked them to get some answers for me, I have not heard back from them in a month so here are the questions passed along to the forum...
Jon1379,
It’s awesome to hear you’re loving your truck. I see that there are already a few great answers. Just to be sure, I asked about your question, and was advised that for the system to cycle back to have no warnings, it would need to be topped off.

For more details, see page 28 of the 2011 F-250 Diesel Supplement 5th printing:
“For either vehicle speed limiting or idle-only condition, normal vehicle operation will resume when the DEF tank is refilled.
Note: When filling the DEF tank from empty, there may be a short delay before detecting the increased level of DEF. This must occur before full power is returned.”

There’s also a disclaimer on page 31 of the same Diesel Supplement that states:

“The tank can be filled using a nozzle at a DEF filling station (similar to fuel fill) or using a DEF bottle with a spout. Motorcraft DEF bottles are recommended as they are designed to be spill proof and will stop the flow of DEF when the tank is full. Other aftermarket bottles can be used, but they should have a seal on the spout and an internal vent tube to achieve best fill performance and prevent overfilling. Overfilling your DEF tank can cause damage to the tank. For DEF capacity, see Maintenance product specifications and capacities in this chapter.”

If you don’t have a digital copy of the Diesel Supplement, it can be downloaded for free by going to Ford, Lincoln or Mercury Owner?s Manual & Maintenance Guides | FLMOwner.com and selecting 2011 F-250 from the drop down menus. Keep on pulling! :)

Cory
 
#8 ·
mmomega, that's the same procedure I use. Usually keep a spare jug in the back(use a plastic milk carton) just to be on the safe side.
 
#9 ·
Thanks for the comments. The good news is nothing is broken. I did see the same notes in the diesel supplement. I did not interpret refill to mean top-off and when nothing happened, I interpreted short delay to possibly mean putting a few miles on.

Lesson learned, the truck is smarter than I am.
 
#10 ·
Like others, who have commented... I also rely on the "System Check" and when it gets below half, I put in another two and a half gallon jug. It has never been an issue for me. Don't worry about the truck being smarter than you... You will learn a lot more about the truck than it will ever learn about you. :lol:

:5:
 
#11 ·
When mine first shows 1/2 tank, It won't hold a 2.5 gallon jug, So I have to give it a week or several good tows after I notice the 1/2 empty so I don't overfil my tank.

I'm kind of "If I open a Jug, I want to use the whole Jug" kinda of a guy. I don't care to have a open jug with a quart of DEF left in it, in the bed of my truck.
 
#12 ·
I keep some full jugs around and rotate them. I try to top off at fueling stations with bulk DEF, just for this reason. And the fact that bulf DEF at Pilot's is usually around $2.59/Gal. I don't even like the 1/2 message to hit, but if it does, I put the 2 - 1 Gal jugs in.

Then again, I also don't like to run my fuel down much past 1/2 full either.
 
#13 ·
Actually just saw BlueDEF at O'Reilleys for $9.90 for 2 1/2 gal.

I've actually towed quite a ways after hitting the half meter just so I could gauge it for future reference and I keep an extra 2 1/2 gal jug in my 5'er if I'm running very low before I get somewhere to buy more. Around DFW there are so many places to get it I don't worry too much but still fill up a little while after hitting 1/2 on sys chk.
 
#15 ·
I just checked my display and sure enough it says it's below 1/2 level with only 2550 miles on the truck.
I never received a message saying I had dropped below 1/2- I guess you have to look to find out.
I've got a fuzzy feeling the dealer didn't top it off, I know the fuel tank was barely full when I drove it off the lot.
 
#18 ·
I just checked my display and sure enough it says it's below 1/2 level with only 2550 miles on the truck.
I never received a message saying I had dropped below 1/2- I guess you have to look to find out...
00buck,
The “Typical Diesel Exhaust Fluid (DEF) Usage” chart is listed on page 36/37 in the 5th printing of the Diesel Supplement which also mentions:

“The charts below illustrate approximate DEF usage for the given distances traveled under various driving conditions and when using the PTO. Your usage may vary depending on: driving style, trailer towing, loaded vehicle weight, weather, idle time, PTO usage, etc.”

For a digital copy of the Diesel Supplement, go to the URL: Ford, Lincoln or Mercury Owner?s Manual & Maintenance Guides | FLMOwner.com and select your truck from the drop down menus to download it for free. Depending on use of the vehicle, that is normal DEF usage.

Cory
 
#16 ·
The DEF tank has a heater to thaw and prevent freezing the inlet line does not. DON'T over fill in cold weather.
I filled up my tank last October....and ran the truck all winter. About Feb I got the CEL light on.

I was taking the truck on a trip, so decided to top up the tank. It was not showing the 1/2 full message.

Guess what, It would only take one quart....and that was 4000 miles later.

The tank had been frozen all winter.

The CEL light did not go out when the warm weather came. I had to wait for the "flash". And it has not been on since that was done in June.

--
Gordon
 
#28 ·
I filled up my tank last October....and ran the truck all winter. About Feb I got the CEL light on.

I was taking the truck on a trip, so decided to top up the tank. It was not showing the 1/2 full message.

Guess what, It would only take one quart....and that was 4000 miles later.

The tank had been frozen all winter.

The CEL light did not go out when the warm weather came. I had to wait for the "flash". And it has not been on since that was done in June.

--
Gordon
DEF is used to eliminate NOx. NOx is generated as a byproduct of heat..
In extremely cold weather, NOx levels are too low to require DEF. and therfore will be full forever...

Summer towing, you'll go thru the normal number. below freezing, probably none.... FWIW
 
#17 ·
Fixdent- that's some funny stuff right there.

I've read ONCE, not a bunch of times just once (on the net so it has to be true-lol) that supposedly truck drivers were getting away with filling their DEF tanks with water.

I never read it again so I blew it off as urban legend.

I wonder if your frozen tank had anything to do with the CEl light being on, did the dealer mention any codes when they reflashed it?
 
#19 ·
I wonder if your frozen tank had anything to do with the CEl light being on, did the dealer mention any codes when they reflashed it?
I thought that may have been the problem, as the light went out later in the winter.

But it started again in May, going on and off every few days.

The Nox sensor was changed and reflashed. It's been off since June.

--
Gordon
 
#24 ·
mmomega, in case you didn't know the Loves on I-20, between I-35 and I-45 has bulk DEF and it's a good bit cheaper. You have to use a small adapter they have, some type of magnet containing adapter to make the pump nozzle work but it's not a big deal...unless you spend 15 minutes trying to figure out why it won't work before going inside and asking, like me.
 
#25 ·
Cool, I'll keep that one in mind. The only time I go that way is when I'm headed to Louisiana. I do have 3 empty 2.5gal DEF jugs in the garage I could fill on the way back from there. :thumbsup:
 
#29 ·
Thanks y2kpsd - good to know.
 
#30 ·
Had the same thing happen. Trip to Fl from Maryland towing camper. I knew my DEF was a little low for the trip so I dropped in 2.5 gallons when I got into NC just for good measure. When I hit the GA/FL border my light came on saying that I have 400 or so miles till my DEF was empty. Hit a Autozone real quick and put in another 2.5 gallons and it filled it all the way up. So I think the sensor is just a little goofy.
 
#32 ·
Mine has said "DEF under 1/2 tank" or something like that.... and I filled it up.

Of course I usually don't wait for all the alarms to go off and its too late, I run thru my "check lights" regularly. Like someone said earlier, the truck isn't supposed to be as smart as you are :)
 
#38 ·
From what I've read , the concern is the fluid freezing and expanding it the filler neck and tube, Not the tank itself. If you fill till you see fluid in the fill port, You will have DEF fluid being held in the filler hose. Which could crack when the DEF freezes.

The Motorcraft DEF bottles include a breather tube that effectively stops the flow of the fluid when the tank is full, so you don't have to fill the tank until you see the fluid over flow. Beside filling the tank neck, it also prevents DEF from overflowing and running down the side of your truck. I have not seen that breather tube on any of the other DEF products. Too bad Ford is so proud of their design that they charge almost double for their DEF vs other makers.
 
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