Crystalized DEF after setting 5 Months

[bowpulpit]

Have a friend who has been winterizing in Arizona for 5 months and left two days ago to head home to Mississippi. I spoke to him today and he is at Freightliner in El Paso because he got a "low def warning" and a check engine light on day one. Although his DEF tank was full, Freightliner told him the problem was DEF had crystalized in his tank after setting in the AZ heat for 5 months. Freightliner plans to empty his tank, check sensors ect which hopefully will fix the problem. In my friends case his tank was about 2/3 full for the 5 months he was here. Ive never heard of this nor seen any posts regarding a problem of this nature so I'm concerned and curious. In my case I've here in AZ for 3 months (leaving for Ohio in 6 days) and wondering if I need to drain and refill my tank. I will say I topped my tank off the day I arrived in AZ so it's been setting full for 3 months. With this post I'm asking if anyone has experienced this problem and had to drain and refilled their tank after setting for several months in a warm climate. TIA

 

[Neal]

If you simply add DEF to the tank to top it off it should resolve the issue.

 

[bowpulpit]

If you simply add DEF to the tank to top it off it should resolve the issue.

Thanks for the reply Neal. My friend did that (put in a jug-2.5 gallons) yesterday and the warning lights stayed on today from Deming to El Paso.

 

[Sealyn]

Possible DEF Head failure, low DEF warning is one of the indications.

 

[MapNerd]

The shelf life of DEF is approximately six months if kept in a cool, dark environment. Less if not. The result when not stored properly or when expired is crystallization.

While AZ can get cool and dark, it also gets really, really hot.

I don’t find this terribly surprising at all. Topping off the tank might help, but not so much if you’re topping off with a container that you picked up off the store shelf because who knows how long that’s been sitting on the shelf?

Best practice is to get DEF in bill from the pump as that has a high turnover and is constantly being cycled through, so you’re getting it as fresh as possible.

Just my ,02. Your mileage may vary.

 

[bobnjill410]

The shelf life of DEF is approximately six months if kept in a cool, dark environment. Less if not. The result when not stored properly or when expired is crystallization.

While AZ can get cool and dark, it also gets really, really hot.

I don’t find this terribly surprising at all. Topping off the tank might help, but not so much if you’re topping off with a container that you picked up off the store shelf because who knows how long that’s been sitting on the shelf?

Best practice is to get DEF in bill from the pump as that has a high turnover and is constantly being cycled through, so you’re getting it as fresh as possible.

Just my ,02. Your mileage may vary.

I personally have had a major issue with getting DEF from the pump at a truck stop. The results of that actually resulted in me needing to towed to Freightliner. The result of this was contaminated DEF from the pump. They analyzed the contents of my tank and found it was contaminated with diesel fuel. I witnessed that as little as a eye dropper of diesel fuel will turn DEF into a milky substance . Result was a new DEF tank and also had to replace the DEF pump.
This very well could have been a one time freaky occurrence, but it was painful to us. I always look at the manufacture date on the Blue DEF before purchase to avoid the long shelf life product. Just passing on a horrible experience we incurred.

 

[MapNerd]

I personally have had a major issue with getting DEF from the pump at a truck stop. The results of that actually resulted in me needing to towed to Freightliner. The result of this was contaminated DEF from the pump. They analyzed the contents of my tank and found it was contaminated with diesel fuel. I witnessed that as little as a eye dropper of diesel fuel will turn DEF into a milky substance . Result was a new DEF tank and also had to replace the DEF pump.
This very well could have been a one time freaky occurrence, but it was painful to us. I always look at the manufacture date on the Blue DEF before purchase to avoid the long shelf life product. Just passing on a horrible experience we incurred.

That does sound like a mind scarring experience

 

[NWIP]

My question is was your friend stationary for the whole 5 months? I think the benefit of moving the coach every 4-6 weeks not only lubricates the engine but helps with DEF issues by circulating the fluid. I winter in South Florida and haven’t had an issue. Sorry to hear of your friends misfortune.

 

[hawlguy]

That does sound like a mind scarring experience

My son also got contaminated DEF at a truck stop pump. Found it had high volume of water in it. Another reason I deleted my truck.

 

[Rich W.]

So a couple quick notes:
1. There is a TSB on older (pre-2016) DEF level sensors and crystalized DEF so yes, a known problem. They can probably clean his DEF header and re-use it.

https://static.nhtsa.gov/odi/tsbs/2013/MC-10142383-9999.pdf

2. There are charts on DEF storage based on time and temp - best to familiarize yourself with that and deciphering the date code on containers.

3. Although the debate on bulk vs store bought DEF continues, you have control over what you buy with off-the-shelf DEF as you can examine the production date and view storage conditions. Bulk suffices for the vast majority, but Ive had problems withmit twice and will not use it in my coach.

4. Keeping the tank full will help, but after sitting for months, I would then drain the tank, flush with a several gallons of distilled water, and refill with new DEF before traveling, especially after sitting in Arizona.

This is the chart I use although my cut-off is one year old. Lately Ive seen some DEF with the date clearly marked, but some still use the ever-confusing year-minus one/reverse-juliian. This is important when trying to buy DEF less than one year old. A good strategy is to buy from higher volume dealers. I decode it by taking the year listed (first two numbers) and subtracting the Julian date (next three). The two letters preceding the date code denote the location of production.