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DEF in the cold

Shimmy1

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Aug 14, 2014
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4,258
Location
North Dakota
So, yesterday it took close to 2 hours before monitor showed the DEF had warmed up. Needed to add some today. Thought about keeping the jug in the cab with me until it warmed up, but figured the warm stuff would help things thaw out sooner. I wasn't working it for more than about 20 min and there it was, DEF abnormality, 59 minutes until the next warning. Still wasn't showing warm after an hour, so then moved on to level 2. Constant beep and 59 minutes until engine derate. Ran about 10 minutes and finally the indicator showed blue, but still code. Shut it off for a few minutes, restarted, still code. Was in the process of calling the shop when it finally went away. I guess it didn't like a nice hot drink in the morning like we do.

2019 PC290-11
 

Simon C

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Jul 1, 2015
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Rocky Mountain House , AB., Canada
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Heavy Equipment Mechanic
Was it minus 34 C like it was in Rocky Mountain House Alberta this morning. I believe the DEF gets warmed by antifreeze on most units. Was your engine running warm.
My Skid Steer has cardboard on both rear side panels to get 165-170 F in this weather. 2022 John Deere 332G with up to date software.
How cold out was it when it did it.
Simon C
 

Coaldust

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May 9, 2011
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North of the 60
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Cargo Tanks, ULSD, RUG, Methanol, LPG
I’ve ran into problems every time a frozen DEF tank was topped off. Almost every time. More often than not. Anecdotally. No proof to back my claim.

The level sensors get confused.

I do recall software updates from various OEM’s trying to fix the issue.
 

BSAA65LB

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Stone Creek, OH, USA
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Most DEF systems have a heating element using coolant to warm the DEF in low temperatures. The level sensors have temperatures sensors as part of the system.

IME, the DEF level sensors tend to be the weak link in the system. In addition, if the DEF actually freezes (below 11 degrees F), the heating system likely does not warm the DEF quick enough to prevent warnings or de-rate.
 

92U 3406

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Western Canuckistan
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Wrench Bender
Place I work has a handful of machines from various brands and so far no issues with derates from frozen DEF and its at least -15°C most of the winter.

I honestly have not seen a whole lot of emissions issues in general on construction equipment. I think the manufacturers have got it dialed in pretty good. We recently had a PSR pulled on one of the units. Just over 30% idle time and to my knowledge it has not had any emission issues in the last 2.5 years.
 

Tags

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Feb 19, 2012
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Connecticut
I thought most DEF tanks had an electric heating element that would keep the tank warm to stop the def from freezing?
 

Birken Vogt

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Joined
Nov 30, 2003
Messages
5,305
Location
Grass Valley, Ca
In addition, if the DEF actually freezes (below 11 degrees F), the heating system likely does not warm the DEF quick enough to prevent warnings or de-rate.

Instead of warnings or derate, they need to uplink and send the manufacturers a fine for building a system that does not function to reduce emissions as intended. Things would get better quick then.
 

mekanik

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Aug 20, 2015
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Canada's Northwest
DEF systems on trucks have a tube that runs through the DEF tank that has coolant running through it. There is a solenoid valve in the coolant supply line to that tube that is controlled by the DEF quality level temperature sensor which maintains the temperature of the DEF. There are heater wires in all the DEF lines that thaw the lines and stop the lines from freezing when operating. I believe there is also a heater in the DEF pump unit. Lots to go wrong!
 

Shimmy1

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Aug 14, 2014
Messages
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Location
North Dakota
Thanks for all the opinions, guys. My guy at the dealer says that the tank has an electric heater as far as he knows. Coaldust saying he's seen issues everytime a frozen tank was added to I think explains it.

What I absolutely can't understand and what pisses me off, is the machine would end up derating because I added fluid to the tank. I mean, WTF? You would think that they would have been able to figure THAT one out by now?
 

BSAA65LB

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Stone Creek, OH, USA
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Retired!
If you added DEF to the frozen DEF in the tank, you are likely confusing the DEF level sensor. The software ultimately decides there is a serious issue and down the de-rate road you go.

Regulations allows you 1 hour to warm the DEF. IME, that can be marginal in some situations. To allow the DEF to thaw and not get into warnings and de-rate, the engine needs to run under a light load. But then you are wasting time and fuel. Use of a block heater or similar seems to be the best way around this situation.
.
 

Shimmy1

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Aug 14, 2014
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Location
North Dakota
If you added DEF to the frozen DEF in the tank, you are likely confusing the DEF level sensor. The software ultimately decides there is a serious issue and down the de-rate road you go.

Regulations allows you 1 hour to warm the DEF. IME, that can be marginal in some situations. To allow the DEF to thaw and not get into warnings and de-rate, the engine needs to run under a light load. But then you are wasting time and fuel. Use of a block heater or similar seems to be the best way around this situation.
.
Must be something to the block heater, even though the dealer says the tank is warmed by electric. The morning it coded I had it plugged in,and it took just a bit over an hour for the icon to turn blue from gray meaning it had reached operating temp. Day before it was warmer, but it took over 2 hours to warm.
 

BSAA65LB

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IME, the tanks are warmed by engine coolant. There is a solenoid on the engine that is turned on/off by the ECU to route warm water to the tank. Usually the DEF lines to the engine are warmed by coolant as well. It works, but the limitation is still the 1 hour regulatory limit to warm the DEF.
 

Oxbow

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Nov 22, 2012
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1,201
Location
Idaho
Most DEF systems have a heating element using coolant to warm the DEF in low temperatures. The level sensors have temperatures sensors as part of the system.

IME, the DEF level sensors tend to be the weak link in the system. In addition, if the DEF actually freezes (below 11 degrees F), the heating system likely does not warm the DEF quick enough to prevent warnings or de-rate.
We have begrudgingly entered the DEF era after postponing as long as possible. I have one pickup and one excavator that use it.

I was concerned about DEF freezing in containers while transporting to job sites, especially those dang (environmentally UNfriendly) jugs in the cardboard box. To my surprise, at -11f degrees, the fluid that sat in the bed of my pickup overnight was still fluid with no signs of slush or gel. I wonder if there are different grades of DEF for cold climates. Surely if there were Shimmy would have that in ND though.

After reading this thread I think that we will make it a rule to try and add DEF only at the end of the day when there are hopefully no issues in the tank.

Edit to add: It sure seems like we use a lot less DEF in the winter. Perhaps because the system bypasses the need for DEF until warm.
 

Truck Shop

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At least on Freightliner's when cold has screwed with the DEF system and codes, I remove the ground
cable for 10 minutes which will clear the DEF light. But our rigs come with auto start when drivers are
parked. And yes DEF warmed by coolant. We run Fargo/Grand Forks trucks don't shut down in the
northern tier during winter.

On a different note-Power Service 911 is only for gelled fuel, the standard Power Service in white jug
is for pre-treating.
 

BSAA65LB

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Stone Creek, OH, USA
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“Edit to add: It sure seems like we use a lot less DEF in the winter.Perhaps because the system bypasses the need for DEF until warm.”

DEF dosing is based on horsepower. Which is measured by throttle position, RPM, exhaust temperature, and NOx before/after the catalyst. There are also calculations made that look at humidity and air inlet temperature, but those are minor considerations. If you are using less DEF in cold weather, it is probably due to cooler exhaust temperature. As long as the NOx stays in range, the system does on slightly lower exhaust temperature.

IMO, filling the DEF tank at the end of the shift is best practice. You know it is full for the next day.

DEF starts to freeze at 11F. I forget where it is fully frozen.

I am not aware of any cold weather DEF. T spec for automotive grade is pretty cut and dried and there is no room for additives. I also know of no additive that lowers the freezing point that won’t screw with your DEF quality.
 

Truck Shop

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Most all the DEF tanks on our tractors hold 23 to 25 gallons, when systems operate properly it goes
a long ways before refill. I can say put DEF in the wrong tank it can cost up to $13,000.00 on a DD15.
 

cuttin edge

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NB Canada
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We used to buy DEF in bulk. It was ok if you pumped directly into the truck, or machine, but if you filled jugs, it seemed to crystalize in the jug. If you only used part of a jug, you get the crystals, in the left over jug. Since we started buying jugs for the machinery, there is still a bulk tank for the trucks, no issues in the warmer weather. A lot of times, if the lines don't drain back into the tank, they will freeze over night. I know lots of guys that just shut down, and kill the master switch before the purge is finished. We have had a lot of issues with the gauge showing a full tank, when it's not full, and in winter, there are multiple drivers, so not always sure if they are full or not. Any trucks that are no longer under warranty, strangely enough their DEF tanks are full of washer fluid, and are trouble free.
 

Oxbow

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Nov 22, 2012
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Idaho
We used to buy DEF in bulk. It was ok if you pumped directly into the truck, or machine, but if you filled jugs, it seemed to crystalize in the jug. If you only used part of a jug, you get the crystals, in the left over jug. Since we started buying jugs for the machinery, there is still a bulk tank for the trucks, no issues in the warmer weather. A lot of times, if the lines don't drain back into the tank, they will freeze over night. I know lots of guys that just shut down, and kill the master switch before the purge is finished. We have had a lot of issues with the gauge showing a full tank, when it's not full, and in winter, there are multiple drivers, so not always sure if they are full or not. Any trucks that are no longer under warranty, strangely enough their DEF tanks are full of washer fluid, and are trouble free.
Washer fluid eh? (Makes mental note to self)!
 
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