# Diesel Exhaust Fluid Frozen?



## pacolino (Aug 1, 2015)

dougc905 said:


> Just noticed that my dic is saying that the diesel exhaust fluid is down to 35%. Problem is, I just poured in a big jug last month. So it should be about 80% full as the def normally lasts me 5-6 months.
> 
> Is it possible that the def tank is frozen and the only fluid available is in the centre reservoir where the heater is? it could be reporting on a diminishing supply with a frozen block of fluid. With our really cold temps, I wonder if the def tank heater is up to the job...
> 
> ...


Def shouldn't freeze no matter how cold is, it's the heater who's not doing the job. 

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## justin13703 (May 2, 2016)

pacolino said:


> Def shouldn't freeze no matter how cold is, it's the heater who's not doing the job.
> 
> Sent from my SM-G930W8 using Tapatalk


Def does start to freeze at around 12 degrees Fahrenheit so it is very possible that depending on the weather conditions and time between drive cycles that it can freeze.

The heater though should have no problem thawing it back out. Try to take a longer than usual trip to give the heater more time, and see if that makes any difference.

Generally DEF usage is related to fuel usage, so if your fuel usage is going up then chances are your def usage is going up also. To determine whether you think the percentage reading is correct though will involve crunching some numbers.

When you say you poured in a big jug, did you actually see the level up at the top of the tank or just pour in what you had? Usually when I fill mine up it takes almost 5 gallons from empty.


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## pacolino (Aug 1, 2015)

justin13703 said:


> Def does start to freeze at around 12 degrees Fahrenheit so it is very possible that depending on the weather conditions and time between drive cycles that it can freeze.
> 
> The heater though should have no problem thawing it back out. Try to take a longer than usual trip to give the heater more time, and see if that makes any difference.
> 
> ...


So what do you think....def freezes while vehicle is parked for a prolonged period of time (outside overnight parking with -20C)?

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## justin13703 (May 2, 2016)

pacolino said:


> So what do you think....def freezes while vehicle is parked for a prolonged period of time (outside overnight parking with -20C)?
> 
> Sent from my LGMS631 using Tapatalk


I’m just saying that it’s possible for it to freeze in those conditions, especially with the weather a lot of us have been having lately. I don’t know if it would cause this issue though. But the heater should take care of it relatively quickly.


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## dougc905 (May 24, 2015)

Update:

The next morning the doc reported that the fluid level was ok. So sometime overnight, or maybe at the end of the drive before the dic was updated, the fluid thawed.


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## Snipesy (Dec 7, 2015)

The EPA (which is what your cruze is made to) allows some grace with frozen DEF. As long as the heater is working (hah!) it should be fine.

Also in my experience if the def is frozen it will jump to around 33% or so,


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## dougc905 (May 24, 2015)

justin13703 said:


> When you say you poured in a big jug, did you actually see the level up at the top of the tank or just pour in what you had? Usually when I fill mine up it takes almost 5 gallons from empty.


Just to go back to reply... I usually top up the tank with a big jug (9.5 litres or 2.5 gal) when I see the fluid level go from saying “ok” to showing a number like 35%. Since the tank holds about twice the jug capacity, I figure that my fluid level varies between 35 and 80% full.


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## dougc905 (May 24, 2015)

Snipesy said:


> Also in my experience if the def is frozen it will jump to around 33% or so,


That’s about what I saw.&#55357;&#56397;&#55356;&#57339;


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## boraz (Aug 29, 2013)

pacolino said:


> Def shouldn't freeze no matter how cold is, it's the heater who's not doing the job.
> 
> Sent from my SM-G930W8 using Tapatalk


umm, itll freeze every time you park if its cold enough

the def heater will thaw it for use.


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## boraz (Aug 29, 2013)

Snipesy said:


> The EPA (which is what your cruze is made to) allows some grace with frozen DEF. As long as the heater is working (hah!) it should be fine.
> 
> Also in my experience if the def is frozen it will jump to around 33% or so,


it needs to be thawed in 70 mins as per the EPA


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## Taxman (Aug 10, 2017)

And it takes what, 5000 BTU to thaw a full tank?
Does that mean the heater is around 1.5kw?

Or does it just have to thaw the area around the pump and start flowing reliably in 70 minutes?


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## boraz (Aug 29, 2013)

Taxman said:


> And it takes what, 5000 BTU to thaw a full tank?
> Does that mean the heater is around 1.5kw?
> 
> Or does it just have to thaw the area around the pump and start flowing reliably in 70 minutes?


dont know how many btus

cant see why it would need to thaw the whole tank, the car barely uses any def and it just needs to be warmer than ~12f to be thawed, so it shouldnt be sooo energy intensive

one could go look at the fuse panel and find the def tank circuit at fuse amps and do the math


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## Snipesy (Dec 7, 2015)

I think the 70 minute rule is just for the EPA's testing. I doubt there is a 70 minute death clock built in, but I could very well be wrong.


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## Sunline Fan (Jul 29, 2012)

With the temps below zero around here all last week, every station with DEF at the pump had frozen pumps. Some tried to thaw out, but they were fighting a losing battle. They even put insulated sleeves around the pumps, but it didn't seem to help much.


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## dougc905 (May 24, 2015)

Sunline Fan said:


> With the temps below zero around here all last week, every station with DEF at the pump had frozen pumps. Some tried to thaw out, but they were fighting a losing battle. They even put insulated sleeves around the pumps, but it didn't seem to help much.


Wow. I bet the station designer never thought of that!


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## Sunline Fan (Jul 29, 2012)

dougc905 said:


> Wow. I bet the station designer never thought of that!


I work right by a Pilot, which happens to have a Subway in it. I was there one day last week and three lanes were down with frozen diesel pumps. One of the employees there said the DEF pumps were frozen, and it didn't look like they weren't even trying to get them working. The (small) eating area for Subway overlooks the fuel islands, so I got to watch as this pump maintenance company tried pumping fuel straight into a 5 gallon bucket. After a few attempts, they didn't even get a drop.


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