Winter and DEF management

[Danishgod]

I am seeking advice from Ram Cummins owners that work in extreme cold temperatures - Canada and northern US states. There is the theory that a DEF tank with a high level of DEF will freeze and will be a problem. How does the team deal with this issue? A local guy here said only fill the tank to a low level and let the internal heater do its job. And a freeze and a thaw causes the DEF to deteriorate.

What are your tactics to deal with DEF in cold weather? Thanks

 

[mtnrider]

Never had an issue with it in Colorado. How cold is it where you are at do do the temps stay freezing and below for extended periods of time?

 

[06 Dodge]

I am seeking advice from Ram Cummins owners that work in extreme cold temperatures - Canada and northern US states. There is the theory that a DEF tank with a high level of DEF will freeze and will be a problem. How does the team deal with this issue? A local guy here said only fill the tank to a low level and let the internal heater do its job. And a freeze and a thaw causes the DEF to deteriorate.

What are your tactics to deal with DEF in cold weather? Thanks

My best guess would be a max of 3/4 full, I'm sure some will say don't worry, but why not error on the side of trying not to spend $$$$

 

[2003F350]

Curious what people are doing, but having been around several trucks with DEF here it doesn't seem to matter whether it's 'full' or not - just don't overfill it. Been through several winters with other trucks and have had no issues, this will be the first winter with this one. If something happens it's under warranty.

 

[Travelin Ram]

You are overthinking this. DEF tanks are designed with headroom at the top. You can’t overfill.

The systems are built to accommodate freezing and thawing.

 

[2003F350]

You are overthinking this. DEF tanks are designed with headroom at the top. You can’t overfill.

The systems are built to accommodate freezing and thawing.

That's honestly what I thought, but having never taken one out to look at it I didn't want to say anything.

 

[jacob302]

The more fluid in the tank, the longer it will take to freeze due to thermal inertia i.e. larger mass of fluid needs more heat removed from it to freeze. I keep mine above 3/4 full all the time and has never frozen for overnight spikes below 12F to single digits.

 

[Dr J Cumminz]

I'm up in Alaska and keep mine between full and half most of the time. I've never had issues with freezing. I think if you are using your vehicle daily you shouldn't have a problem, especially if it's full since it would take a while for the mass the freeze versus at half level. Whereas, if you are going on vacation and you have 1/4 - 1/2 for a week or 2 in extreme cold weather (for us it's -10 to -30) then I'd probably fill it up to at least 3/4 to account for expansion and time-to-freeze ratio.

 

[Calicajun]

I have been re-filling my DEF tank whenever it gets to the half way point. Do this because I'm worried about condensation building up in the tank and creating water. Water in the DEF tank I have been told is very bad as it is in the fuel tank. Though I'm also worried about freezing as we are starting to RV full-time and I'm sure there will be a wrong turn or decision that will end us up in the wrong area.

 

[megabass2]

I am seeking advice from Ram Cummins owners that work in extreme cold temperatures - Canada and northern US states. There is the theory that a DEF tank with a high level of DEF will freeze and will be a problem. How does the team deal with this issue? A local guy here said only fill the tank to a low level and let the internal heater do its job. And a freeze and a thaw causes the DEF to deteriorate.

What are your tactics to deal with DEF in cold weather? Thanks

I live in Saskatchwan ,Canada where it can get down to -40 F occasionally but well below 0 F very regularly. My dealers service department has said not to fill my def tank on my 2022 Eco diesel past the 3/4 mark in the winter. Probably the same for 3/4 ton Cummins.

 

[JosephPukala]

It was a blistering 59 this morning in SW Florida. My intake heater thought about preheating and then it was like I’m getting a piña colada I’ll see you by the pool.

 

[06 Dodge]

I have been re-filling my DEF tank whenever it gets to the half way point. Do this because I'm worried about condensation building up in the tank and creating water. Water in the DEF tank I have been told is very bad as it is in the fuel tank. Though I'm also worried about freezing as we are starting to RV full-time and I'm sure there will be a wrong turn or decision that will end us up in the wrong area.

I don't refill mine DEF until it gets at or below 1/4 and so far up here in the Portland Or area, I have not had any problems with condensation that has diluted or caused problems with my DEF since I bought the truck in March of 2022...

 

[lpennock]

I have been re-filling my DEF tank whenever it gets to the half way point. Do this because I'm worried about condensation building up in the tank and creating water. Water in the DEF tank I have been told is very bad as it is in the fuel tank. Though I'm also worried about freezing as we are starting to RV full-time and I'm sure there will be a wrong turn or decision that will end us up in the wrong area.

Condensation really isn't an issue. DEF is about 70% water anyway so the condensation is just the water that evaporated out of the DEF going back into the DEF.

 

[runamuck]

new to diesel trucks so looking for cold weather tips. will be making a trip or two to the mountains for skiing and truck will be sitting 0-5* every night for a few days. I dont have the crankcase heater option. do I need to add one.

 

[lpennock]

Check you owners manual and make sure you are running the correct oil viscosity grade for the low temps you are expecting. Preferably run a full synthetic oil as they flow better when cold. Crankcase heater will make starting easier but if you are running the correct oil it isn't really required at 0F.

 

[crash68]

new to diesel trucks so looking for cold weather tips. will be making a trip or two to the mountains for skiing and truck will be sitting 0-5* every night for a few days. I dont have the crankcase heater option. do I need to add one.

The block heater itself should already in the block, it's located just behind the oil filter. You probably just need the cord which can be bought fairly cheap. https://www.genosgarage.com/product/heater-cable-fl/winter
As mentioned above you'll want to have 5W-40 full synthetic oil in the crankcase (per owner's manual).
A winter front cover would also be ideal if driving in temps around 0°F, the engine will get up to and stay at operating temperatures quicker. If your towing a load it's probably not needed. Vehicle occupants will be appreciative of heat in the cab.

 

[Dean2]

Cold weather and in colder than -20, DEF freezes overnight whether it is 1/4 full or completely full. You also have to remember that the larger mass takes longer to thaw.

Like anything that has water in it, it expands when it freezes. Most of the guys I know never have it more than 3/4 full. Ipenock is right, condensation in the DEF tank is a non-issue but it is wise to keep your fuel tank full because condensation there is not good. Especially important if you park in a heated garage.

As to block heaters, as soon as it goes below freezing, block heaters are a good idea. It is far easier on the motor to have some heat in it, and there is no downside to using it, except for a bit of electricity. Put it on a timer and have it come on 2 hours before start, extend the time the colder it gets, at -30 and colder we run them all night.