DEF Issues

[dedmiston]

I drove a RAM 2500 diesel for 12 years until I upgraded to a pre-owned 2014 3500 diesel earlier this year. I knew nothing about DEF when I bought the "new" truck in March. My first introduction to DEF was when I saw the extra gauge on the dash and the filler inside the gas cap door. Well whadda ya know? I caught on quickly enough and filled the DEF tank as needed.

Fast forward to last week...

We left on a trip last week to go white water rafting up on the American River up in the gold country. I noticed before we left that the DEF level was just below 3/4 and didn't give it much more thought. Off we went.

Coming down the back side of the Grapevine I noticed that the check engine light was on and the DEF gauge showed it was empty. Oh no. I stopped at the next gas station and bought a few jugs of DEF to refill. By then a message popped up and told me "5MPH Max Speed in 150 mi. Service DEF System. See Dealer."

Swell.

I managed to get about three gallons of DEF into the tank before it overflowed. The needle stuck at Empty though.

So we limped to Bakersfield and spent the night at an RV park down the street from the Dodge dealer. The next morning the folks at the Dodge dealer took four hours to check it out and declared that everything was just fine and the message was bogus. They reset the errors and sent me on my way.

We had about five hours to go from there. About an hour away I noticed that the needle was down to 3/4 tank. That was fast. I tried to add more when we stopped for fuel, but the tank was full and I couldn't fill it any more.

Over the next few hours the needle fell quickly until it finally got past the red again and gave us a similar message: "Speed Limited to 5MPH in 200 mi. Refill DEF."

Luckily our destination was only about 20 miles away, so we got to camp and sent in to the closest dealer the next morning for service. They diagnosed it and said that the DEF pump was faulty. They replaced the pump and the sensor (part of the pump).

The service writer there was much more knowledgeable than the one in Bakersfield. She said that the sensors aren't mechanical, they're sonar. The sonar sensors run into trouble if you refill the DEF too soon.

"DEF level sensors operate off a sonar sensor and must see an air gap before level will actually drop. Filling the tank before it reaches the 1/2 way mark, we have seen issues with it detecting incorrectly and can set a fault in system. To prevent this we just recommend not filling the tank unless it is between the 1/4 and 1/2 mark. The only other thing that I can think of that might really help and prevent possible issues is to ALWAYS use your exhaust brake. Make it a habit to turn it on as soon as you get into the vehicle. This will help to reduce carbon build up in the exhaust brake and keep it working properly... saves your brakes."

I thought I'd check here and see if this jives with everyone's understanding. And if so, are there other things I should keep in mind with the newer diesel?

I also noticed on this trip that almost all of the gas stations along I-5 and I-99 sold biodiesel instead of good old #2 diesel. Is this kosher? Anything I should be concerned about?

[tinner12002]

dedmiston wrote:
Interesting consensus from all of you on the exhaust brake. I use it whenever I tow, but rarely use it otherwise. It seems like the exhaust brake scrubs off enough momentum on the downhills to negatively impact fuel economy. Maybe that's in my head though.

What about DEF usage when towing vs. not towing? I don't really notice the gauge drop very much, but it seems to drop quicker when I'm towing. I can't tell if that's real or if it's just in my head.

I believe that's normal consumption for DEF as mine also uses considerably more when towing. When not towing I hardly use any. Haven't experienced any warnings though and I've filled mine when it was about 1/2 full. Usually fill DEF up when starting a trip regardless of how full it is. I always carry 2.5 gal with me just in case...always buy mine at wally world.

[SoCalDesertRid1]

I remember when the exhaust brake was recommended to run at all times with the 2007-up Cummins 6.7 with EGR/DPF emissions system, to keep the turbo, etc from clogging with soot. I thought that issue was fixed when Cummins went to the SCR/DEF emissions system?

International got into alot of problems when they went exclusively with EGR/DPF on all their engines after 2003. They finally bit the bullet and went to SCR/DEF recently.

I was very careful to pick a 2002-down truck when I decided I wanted a commercial truck with an International (DT466E) diesel, so there would be no issues with EGR/DPF.

That said, our '05 E350 with 6.0 International VT365 diesel didn't have any issues with the EGR/DPF system, up through the time we sold it in '15.

[blofgren]

I wait until I'm under 1/2 tank of DEF before I top it up mostly to reduce the age of the fluid. Then I will add one "box", usually from Walmart.

I have used bulk DEF from a truck stop a couple of times as well with no issues. The main reason I stopped using it is because it flows so fast it is almost impossible to prevent it from overflowing all over the side of the truck.

The DEF gauge on the Ram is very approximate and conservative so don't be afraid to run it down to 1/2 tank or less before refilling.

[ShinerBock]

FishOnOne wrote:

Perhaps you did explain it but I'm fully aware how these systems work and the problems they have. Having said that, my '12 uses more EGR than my 05 Powerstroke, but the fix to the sticking vains was a simple one and that was to cycle them while the truck is idling. I can actually here it occurring on my '12 since the engine idles so quite.

The Cummins VGT vanes cycle as well, and have even before SCR/DEF. Especially when the engine is cold since closing the sliding nozzle causes back pressure which causes the engine to warm up quicker. However, it was the addition of SCR/DEF system that made the made the soot clogging the sliding nozzle a thing of the past since less soot was created due to not utilizing the EGR as much.

[FishOnOne]

ShinerBock wrote:

FishOnOne wrote:


I change the oil between 5,000 - 7,500 miles.

Oh, that is why. I can go about 5,000-6,000 miles between DEF fill ups. But no where near my 15k mile oil change intervals.

FishOnOne wrote:
The 6.0 PSD I had never had the turbo touched, but I did replace the EGR valve at 80k miles and cleaned the EGR valve at 160k miles due to soot clogging the valve. The symptom is the truck would run sluggish and blow black smoke at low rpms.

Soot on the VGT vanes was a common problem with the 6.0L. So common in fact that even PowerstokeHub lists it as on of the issues of the 6.0L.
6.0L POWER STROKE PROBLEMS

FishOnOne wrote:
I've yet to hear of any vains getting stuck on the 6.7 PSD. My '12 requires to have the truck running in Tow/Haul mode for it to work, but I don't like to run it in this mode while driving around town.

That is because the SCR/DEF system. Since your truck is equipped with a SCR/DEF system, it does not need to utilize the EGR as much to reduce NOx creating less soot. Since the 2007.5-2012 Cummins did not have an DEF system, the EGR was over utilized to meet emissions which created a lot of soot. That is of course gone with the addition of a SCR/DEF system on the 2013+ Cummins trucks. I thought I explained this to you a few times before?

Perhaps you did explain it but I'm fully aware how these systems work and the problems they have. Having said that, my '12 uses more EGR than my 05 Powerstroke, but the fix to the sticking vains was a simple one and that was to cycle them while the truck is idling. I can actually here it occurring on my '12 since the engine idles so quite.

[ShinerBock]

FishOnOne wrote:


I change the oil between 5,000 - 7,500 miles.

Oh, that is why. I can go about 5,000-6,000 miles between DEF fill ups. But no where near my 15k mile oil change intervals.

FishOnOne wrote:
The 6.0 PSD I had never had the turbo touched, but I did replace the EGR valve at 80k miles and cleaned the EGR valve at 160k miles due to soot clogging the valve. The symptom is the truck would run sluggish and blow black smoke at low rpms.

Soot on the VGT vanes was a common problem with the 6.0L. So common in fact that even PowerstokeHub lists it as on of the issues of the 6.0L.
6.0L POWER STROKE PROBLEMS

FishOnOne wrote:
I've yet to hear of any vains getting stuck on the 6.7 PSD. My '12 requires to have the truck running in Tow/Haul mode for it to work, but I don't like to run it in this mode while driving around town.

That is because the SCR/DEF system. Since your truck is equipped with a SCR/DEF system, it does not need to utilize the EGR as much to reduce NOx creating less soot. Since the 2007.5-2012 Cummins did not have an DEF system, the EGR was over utilized to meet emissions which created a lot of soot. That is of course gone with the addition of a SCR/DEF system on the 2013+ Cummins trucks. I thought I explained this to you a few times before?

[FishOnOne]

ShinerBock wrote:

FishOnOne wrote:
I add DEF fluid at every oil change which is typically 2 gallons using only DEF from a container and at 96k miles no issues to date. And for the naysayers it doesn't mean I would have problems using bulk DEF, but I'm just more comfortable with the container stuff.

You only fill up every oil change? How often are you doing your oil changes. There is no way I could go 15k between DEF fill ups.

FishOnOne wrote:
Running exhaust brake is still a common practice on the 6.7 cummins to prevent soot build up in the turbo

LOL!!! Too bad the 6.0L Powerstrokes didn't have exhaust brake to "clean the soot build-up" on them since they were prone to soot build up on the VGT veins. I wonder if you have to run the exhaust brake on the new Powerstroke since it is VGT now too.

I change the oil between 5,000 - 7,500 miles.

The 6.0 PSD I had never had the turbo touched, but I did replace the EGR valve at 80k miles and cleaned the EGR valve at 160k miles due to soot clogging the valve. The symptom is the truck would run sluggish and blow black smoke at low rpms.

I've yet to hear of any vains getting stuck on the 6.7 PSD. My '12 requires to have the truck running in Tow/Haul mode for it to work, but I don't like to run it in this mode while driving around town.

[Cool_Canuck]

DEF is used to break down NOx which is created when running hot. That is why you use more while towing.

Soot in the exhaust is created while running cool and therefore more exhaust cleaning activity when not towing.

DEF has nothing to do with soot.

[ShinerBock]

FishOnOne wrote:
I add DEF fluid at every oil change which is typically 2 gallons using only DEF from a container and at 96k miles no issues to date. And for the naysayers it doesn't mean I would have problems using bulk DEF, but I'm just more comfortable with the container stuff.

You only fill up every oil change? How often are you doing your oil changes. There is no way I could go 15k between DEF fill ups.

FishOnOne wrote:
Running exhaust brake is still a common practice on the 6.7 cummins to prevent soot build up in the turbo

LOL!!! Too bad the 6.0L Powerstrokes didn't have exhaust brake to "clean the soot build-up" on them since they were prone to soot build up on the VGT veins. I wonder if you have to run the exhaust brake on the new Powerstroke since it is VGT now too.

[FishOnOne]

I add DEF fluid at every oil change which is typically 2 gallons using only DEF from a container and at 96k miles no issues to date. And for the naysayers it doesn't mean I would have problems using bulk DEF, but I'm just more comfortable with the container stuff.

Running exhaust brake is still a common practice on the 6.7 cummins to prevent soot build up in the turbo, but not a good idea when driving on slippery road surfaces.

B20 is accepted but draining the water separator more frequent wouldn't hurt, but is not required by the mfg.

[Perrysburg_Dodg]

Glad you got it straighten out. I have always ran my def down until the "Fill DEF" light comes on.

It is sitting just under 1/4 of a tank in the red with 1000 miles until the next oil change. Will fill it next week and then change the oil. Mine uses one tank every 10,000 miles or every oil change.

Don

[Cummins12V98]

EB on ALL the time? YES

Wait til DEF gauge is down to 1/2. Then a 2.5 DEF jug will fit.

B20 or less is just fine.

Do not agree with Dealer comments on fill times.

[Huntindog]

IdaD wrote:

Me Again wrote:
I wish one could default the exhaust brake to be on all the time. When towing it restarts in Tow/Haul but not exhaust brake.

Ditto. I often find that I drive a few miles before I remember, and I'm going to wear the stupid switch out because I have to turn it on every time. A minor quibble but I wish it would remember the last setting before you shut it down.

The reason it is like that is certain road condition can be dangerous with the EB activated.

[IdaD]

Me Again wrote:
I wish one could default the exhaust brake to be on all the time. When towing it restarts in Tow/Haul but not exhaust brake.

Ditto. I often find that I drive a few miles before I remember, and I'm going to wear the stupid switch out because I have to turn it on every time. A minor quibble but I wish it would remember the last setting before you shut it down.