NOx Conversion / DPF Ash Volume

Ericka Natali 34 posts since May 14, 2015
NOx Conversion / DPF Ash Volume Apr 6, 2020 11:37 AM
Good Morning!
I hope everyone is healthy in the land of DTNA Solutions!
We had Vin FM7189 DD15GHG14 come in on Friday with active faults
3226/2 Outlet NOx drift 3216/31 Inlet NOx drift 4364/1 &18 NOx conversion efficiency low / very low &
3 regulatory faults. Tech went through the troubleshooting, software levels in spec, replaced required
sensors and performed multiple regens as required. All faults cleared, except 3 active regulatory. At no point
was there a fault for DPF ash accumulation / maintenance. Troubleshooting does not direct tech to check
filter %, checked just to see what level was at and found 95% full. Just before unit was shut down active fault
5397/31 regen too often popped up. Anyone know what may cause the fault to not show up? Just curious if
anyone else is running in to this.

Jon Cecil 881 posts since Nov 25, 2014
Re: NOx Conversion / DPF Ash Volume Apr 6, 2020 2:07 PM
5397/31 may have become present because of multiple regens being done. If the unit is having regen issues or
not, I would reference SS 469443 Successful Regen Reference for GHG14 DD Engines. Was there any soot
in the outlet pipe of the one box?

Ericka Natali 34 posts since May 14, 2015
Re: NOx Conversion / DPF Ash Volume Apr 10, 2020 12:01 PM
No there wasn't - See addition to the this post below

James McFadden 157 posts since Dec 9, 2014
Re: NOx Conversion / DPF Ash Volume Apr 6, 2020 2:15 PM
a fault for dpf ash clean request will become active when its 100% full. I have had this issue multiple times to
find out that the dpf was at the end of service life and needed replaced with a clean reman . nox conversion
can be affected by a multitude of things this being one of them . the problem is t/s don't lead that direction . its
a good guide but not always the fix. also when the dpf are end of life and is actually full of ash and soot I have
found soot passing dpf due to cracks in substrate from unintentional ignition of soot and have had very high
temps at dpf outlet .. "codes in acm" then the soot passes into scr system and by then its to late .

Scott Trippel 3,990 posts since Dec 13, 2014
Re: NOx Conversion / DPF Ash Volume Jul 6, 2020 1:31 PM
No idea why this happens Erika?

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NOx Conversion / DPF Ash Volume

I have had other faults pop up as well and not show as logged, I guess we could blame software?

Ericka Natali 34 posts since May 14, 2015
Re: NOx Conversion / DPF Ash Volume Apr 10, 2020 12:36 PM
Any thoughts Scott?

Ericka Natali 34 posts since May 14, 2015
Re: NOx Conversion / DPF Ash Volume Apr 10, 2020 12:34 PM
* * * UPDATE * * *
Vin: FM7189 - Pulled DPFs - questionable fluid staining. More interesting find - Inside bottom of OneBox,
3-4" of white liquid. Pulled sample - No Coolant, No Fuel - Refractometer shows water - No urea. Double
checked DEF quality in tank and it is spot on at 32.5%. Let sample from inside OneBox sit overnight - No
crystals, water evaporated leaving behind a silky white powder (talcum consistency) OneBox still has 2 - 2.5"
of fluid inside this morning. DPFs left wet spots on workbench indicating moisture in filters. Anyone seen this?
Thoughts?
Fluid & Moisture in One Box

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NOx Conversion / DPF Ash Volume

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NOx Conversion / DPF Ash Volume

Scott Trippel 3,990 posts since Dec 13, 2014
Re: NOx Conversion / DPF Ash Volume Apr 13, 2020 1:49 PM
The fluid looks like oil mixed with water, I think The specified item was not found. has a good question does the
fluid feel slippery? I think we are both wondering if the engine is using any oil?
The one we have in the shop here that the DPF and DOC are stained we found injectors failed. On ours
though we had over temperature codes for the DOC and DPF.
My feeling on this is when you find the answer it may be something that does not come to mind.
Is there any sign of backwards running engine? So melted intake manifold temp sensor, smell of exhaust in
left CAC pipe?
What I also find interesting is your original statements you say the tech performed many regens, I would think
any fluid would be cooked out of the 1 box? By this time, maybe Kyle Siebert has a good point, was the truck
in a flood...it is a thought.
When doing a regen is there a lot of steam from the exhaust pipe?

Kevin Flottmeyer 171 posts since Nov 11, 2014
Re: NOx Conversion / DPF Ash Volume Apr 10, 2020 6:15 PM
Is DEF in the DEF tank cloudy? We had a customer that was storing the DEF in a unheated shop and overtime
the DEF became cloudy and was causing issues in the 1 box. I can't remember what the codes were but it was
determine that the cloudy DEF was the problem.

Kyle Siebert 4,084 posts since Nov 14, 2014
Re: NOx Conversion / DPF Ash Volume Apr 10, 2020 7:19 PM
Any chance the truck was parked in like 2 or 3 feet deep of water? You could drain the rear ends
a little to see if water has collected in the bottom of them. Those would be the next lowest entry
point of water. If there is no hose on the breather, water can get in to the rear end. Seems like
water can get in thru the tailpipe and drain hole in the one box. I haven’t dealt with flooded
trucks with emmissions. But I had a fleet of dt466 box trucks that were 4 feet deep in water.
It would make sense that water collected inside would affect SCR efficiency. Plus with the he’s
source above the water surface it wouldn’t evaporate out as quick as one would think as it’s a
pretty good insulator to the above heat source. I know the drain hole is in the rear but I don’t
think it would drain in the front section and decomp tube area. I think it just drains in the SCR
outlet area.

Ericka Natali 34 posts since May 14, 2015
Re: NOx Conversion / DPF Ash Volume Apr 17, 2020 5:33 PM
So for the delay in response - It's been a hectic week.

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NOx Conversion / DPF Ash Volume

No fluid is not slippery, doesn't crystallize or have a smell. Oil level is in spec, no sign of contamination. When
fluid dries, silky talcum like powder is left behind. No over temp codes, No signs of running backwards. No
exhaust smell from CAC pipe.
Regens were done during troubleshooting and fault code for regen too frequent went active. No steam or
smoke which we also thought was odd after finding the liquid. Seems like it would have burned off during the
regens, set an over temp code or cracked filters or DOC. Driver said he had to do 2 parked regens during
his journey from FL to NY. As far as flood conditions - I have no idea.

Kyle Siebert 4,084 posts since Nov 14, 2014
Re: NOx Conversion / DPF Ash Volume Apr 18, 2020 2:16 AM
Its actually not surprising the fluid didn't burn off. Heat rises, so sitting at the bottom of the one box its gonna
stay cool. Water is also a good insulator, so hot air above it wont penitrate past a millimeter or 2 below the
surface. And no convection currents to carry the water molecules around to heat them all up. That's why
boiling water in a pot is so effective. Heating the bottom of the pot, the hot water molecules rise up and the
cold ones fall down. Now if there was water in the DOC inlet chamber, that would be shocking as the air under
it is being heated by the SCR inlet gasses underneath it.

Donald Warman 2 posts since Nov 7, 2018
Re: NOx Conversion / DPF Ash Volume Jul 5, 2020 3:18 AM
I think the dpf filters are an unglazed ceramic, if they were submerged in water for a time then allowed to drain
the ceramic itself would be saturated. When heated during a regen it would brake down this could explain the
white talcum like powder you found. run a light box and air flow test on them if you have access to a cleaning
station.

Serge Grandmont 41 posts since Jan 22, 2015
Re: NOx Conversion / DPF Ash Volume Nov 13, 2020 2:09 AM
Have you checked with a inspection camera if you have white dust in bottom of def tank.... we have a couple
units in the past with white dust or some kind of paste. def pump filter was plugged up with it. def test strip
would not pick it up. Still don't know what that stuff is today. If you have this, please update me

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