DEF Issues!!

[Miller205]

I am seeing a trend of DEF issues with my coach that is really troublesome. The first one was for a DEF tank heater sensor failure – very expensive repair. Now we are on the road 800 miles from home, and a new CEL indicating low or no flow to the DEF pump. Online research indicates it’s likely crystallized fluid in the lines. I need to get it fixed before we move on because it appears that the engine will start to derate if I continue to drive it with the CEL illuminated with this failure.
Anyone else having these types of issues? Is it because of the heat, cold, storage? Any suggestions would be appreciated. I’m growing weary of spending money on DEF related failures. 😠

[THenman]

No ideas but you might include Engine and year, perhaps even coach model.


Tom

[Miller205]

2013 Jayco Embark with Cummins ISC 8.3L

[jimcumminsw]

How often do you put DEF in the tank and where do you purchase the DEF from?

[hamm2018]

DEF will go bad. There is an expiration date for DEF. I am not sure how long it is good, but I have just seen somebody put a full box in the trash when I was there. He told me it was expired and he did not want to take the chance.

If you get it at a truck stop I am not sure how you would know the date, but they may think it would be used before the date expires.

[Itchytoe]

Originally Posted by Miller205

Anyone else having these types of issues? Is it because of the heat, cold, storage? Any suggestions would be appreciated. I’m growing weary of spending money on DEF related failures. 😠

If DEF stays in storage and doesn't flow, small crystals can form. Sometimes they redissolve, sometimes they don't. Those crystals can hinder flow and give you the symptoms you're seeing. Storage is the most likely cause of your issues, but the cold can also cause the crystals to form. DEF freezes completely at about 15F, and it gets slushy around 32F (IIRC). It gets very unhappy when it's cold. Basically, if it's cold enough for you to get a coat, it's cold enough for DEF problems.



Yes, your vehicle will go into limp mode if DEF issues are not fixed pretty quick. Pickup trucks are limited to about 50 mph and 2,000 RPM or something similarly underpowered. Your rig will probably do the same.



My suggestion is to take your rig some place bumpy and see if the DPF and SCR systems will fall off when you hit a bump. It's unfortunate, but that happens sometimes. If they fall off, they can't fail again right? You don't live in California do you?

[Miller205]

I live in Virginia, but camping in Springfield, IL right now

[Miller205]

Well, as things devolve from bad to worse, the stop engine light came on as I tried to leave the campground to take to repair shop - no power above idle. So, it’s mobile service or the truck at this point

[jimcumminsw]

You never did stated how often you add DEF to the motor home and where did you purchase this from! Why?

[Miller205]

I usually get it at Walmart. I haven’t had to add any since late last year when I put it into storage for the winter

[grindstone01]

For long term storage, it seems like the DEF tank should be stored as empty as possible and refilled with fresh DEF when taken out of storage.

[jimcumminsw]

Here is a link from FORD motor company about DEF storage. That all should read! https://www.fcsdchemicalsandlubrican...%20Quality.pdf

I am sure Walmart does not follow all of these recommendations when storing DEF. I would not purchase DEF from Walmart at all, just my opinion.

Some user of trucks that require DEF and having issues have clean the systems and have had no other issues. Such as cleaning the filter and injector pump to name a few things.

[NevadaNick]

Walmart sells such high quantities that storage is not an issue. I have never had a def quality problem ever. I have had a def system issue in my 2011 GMC and a def heater problem in a Mercedes suv.

[Miller205]

Originally Posted by jimcumminsw

Here is a link from FORD motor company about DEF storage. That all should read! https://www.fcsdchemicalsandlubrican...%20Quality.pdf

I am sure Walmart does not follow all of these recommendations when storing DEF. I would not purchase DEF from Walmart at all, just my opinion.

Some user of trucks that require DEF and having issues have clean the systems and have had no other issues. Such as cleaning the filter and injector pump to name a few things.

So what’s involved in cleaning the filter and pump?