2016 Ford DEF question (problem)

[The Evil Twin]

Hey oil burners!
Weird situation happening with my truck. The DEF indicator will read OK at times. Then, randomly I will get 500 miles to go. Sometimes that will keep counting down for a few key cycles and magically return to OK while I'm driving down the road. At no time do I ever see *under 1/2". This morning it said 467 miles to go as I left for the dump. When I left the recycling facility it was OK.
There are 2,900 miles on the tank of DEF and the last time I filled it was at Royal Farms DEF pump. I put in 4.2 gallons. So I know it was full 2900 miles ago.
Before I fill it again to see if it sorts itself out, any suggestions on what to check? I don't want to have to drop the tank while full if I can avoid it. Lol! There hasn't been any work done on the truck recently. No off road adventures. No water crossings. The only unusual thing was me filling from a DEF pump instead of Tractor Supply brand jugs. All the connectors I can reach are snugly in their home. I have a trip coming up in 6 weeks. Don't want to be de-rated pulling 6 tons 1000 miles from home.
Thanks for any assistance.

 

[Fordtech86]

It’s most likely the sender in the tank. I think there is/was an extended coverage on some of those (I’m not in the diesel shop anymore). PM me the vin and I could check it for you if you want.

 

[The Evil Twin]

It’s most likely the sender in the tank. I think there is/was an extended coverage on some of those (I’m not in the diesel shop anymore). PM me the vin and I could check it for you if you want.

Incoming!

 

[lynnmor]

There is an extended warranty on the DEF heater, I don't know if a sender problem is included.

 

[The Evil Twin]

There is an extended warranty on the DEF heater, I don't know if a sender problem is included.

Good point. The heater is integrated into the sending unit. But, since the heater isn't the problem......
Though, I do have an excellent relationship with my dealer. If Fordtech86 comes back with the news that it's only for the heater, I may be able to slide this in.

 

[Fordtech86]

There is an extended warranty on the DEF heater, I don't know if a sender problem is included.

it covers both

 

[Daren Todd]

It’s most likely the sender in the tank. I think there is/was an extended coverage on some of those (I’m not in the diesel shop anymore). PM me the vin and I could check it for you if you want.

Or corrosion at the quick connect where it goes into the tank. We had a similar issue with the fuel sensor on one of our service trucks

It had gotten packed fulled of mud, dirt and crud.

Driver was headed down the highway, filled up, so he should have been down to around d 7/8 of a tank based on distance from the shop.

All of a sudden it flashed 50 miles till empty. About 10 miles down the road the fuel Guage dropped to below E and the truck shut off on him on the interstate.

An old man picked him up and gave him a ride to get a 5 gallon can of diesel and then toted him back to the truck.

After adding truck only would take 4 gallons of the diesel

They had the truck towed. Dealership called the next day and and said it was all fixed. The quick connect at the fuel tank was packed full of crud

 

[jimh406]

Other liquids like diesel gasoline etc, can go bad. I'm pretty sure DEF expires.

I don't have a DEF vehicle, but my guess is there is some type of supplement made by someone to help clear/clean the system. I'd look into that.

 

[The Evil Twin]

Or corrosion at the quick connect where it goes into the tank. We had a similar issue with the fuel sensor on one of our service trucks

It had gotten packed fulled of mud, dirt and crud.

Driver was headed down the highway, filled up, so he should have been down to around d 7/8 of a tank based on distance from the shop.

All of a sudden it flashed 50 miles till empty. About 10 miles down the road the fuel Guage dropped to below E and the truck shut off on him on the interstate.

An old man picked him up and gave him a ride to get a 5 gallon can of diesel and then toted him back to the truck.

After adding truck only would take 4 gallons of the diesel

They had the truck towed. Dealership called the next day and and said it was all fixed. The quick connect at the fuel tank was packed full of crud

My truck is pretty darn clean underneath. I did already check the connector on top of the cat pee tank. I was hoping it would be something dumb.

 

[The Evil Twin]

Other liquids like diesel gasoline etc, can go bad. I'm pretty sure DEF expires.

I don't have a DEF vehicle, but my guess is there is some type of supplement made by someone to help clear/clean the system. I'd look into that.

DEF definitely does "expire". It's based on time and temperature. This tank is not even 2 months old. Nothing should ever be added to the tank, except for more DEF. It is nothing but distilled water and urea.
The station I got it at serves truckers also. I know it's high turn over. I've had old DEF run just fine. I would expect an issue with the stuff I got at the station would have shown up much sooner. Not 2 months and 2900 miles later. Anything is possible though. Based on Fordtech86 info, I'm going to keep my Torque Pro handy for the next time it says 500 miles.

 

[JasonW]

My 16 F250 did something similar beginning of last year. Got a CEL for the DEF level indicator.

I bought the truck used but I called my local dealer about the recall and to schedule an appointment. They confirmed it was covered under the DEF heater recall since the level sensor and such is all one unit.

Go to make a appointment for that week or the next week and the dealership tells me warranty repairs are on a different list, gives me a date that’s over 6 months out.

Now the truck was at 85% soot level and will not regen with that CEL on. So if it hits 100% and can’t regen I’m sure it will put it in limp mode leaving me stranded if it would even run at all.

Decided to fix it myself, took about a week for parts to arrive. Trouble free since.

 

[lugbolt]

y'all are reminding me that my old 7.3, although slow as christmas, noisy, smoky, and outdated-cannot be replaced. 254,000 miles and counting but I don't drive it much anymore. I gotta put brakes and injectors in it at some point.

 

[The Evil Twin]

My 16 F250 did something similar beginning of last year. Got a CEL for the DEF level indicator.

I bought the truck used but I called my local dealer about the recall and to schedule an appointment. They confirmed it was covered under the DEF heater recall since the level sensor and such is all one unit.

Go to make a appointment for that week or the next week and the dealership tells me warranty repairs are on a different list, gives me a date that’s over 6 months out.

Now the truck was at 85% soot level and will not regen with that CEL on. So if it hits 100% and can’t regen I’m sure it will put it in limp mode leaving me stranded if it would even run at all.

Decided to fix it myself, took about a week for parts to arrive. Trouble free since.

Good to hear! I haven't had a chance to plug into the truck yet, but the MIL hasn't lit up. Yet. The Bosch unit is only $260 and they aren't terrible to replace. I just don't want to throw parts at it without a solid trouble code. Unfortunately, time is limited in the summer. I can't go chasing ghosts. Fortunately, if/ when I take it to the dealer, they don't have two different lists.

 

[JasonW]

Good to hear! I haven't had a chance to plug into the truck yet, but the MIL hasn't lit up. Yet. The Bosch unit is only $260 and they aren't terrible to replace. I just don't want to throw parts at it without a solid trouble code. Unfortunately, time is limited in the summer. I can't go chasing ghosts. Fortunately, if/ when I take it to the dealer, they don't have two different lists.

Sent you a PM.