Sprinter Gurus ONLY Educate me about Sprinter passive regenerations.

Specifically, under what operating conditions do "Passive" regenerations occur? Please provide manufacturer's documents to support your claim(s).

I might not be a Sprinter "Guru" - but in can tell you that after over 70,000 miles monitoring the exhaust gas temperature going into and out of the DPF the Sprinter does not do passive regeneration. The DPF is located too far from the engine combustion to get hot enough for passive regeneration. Other diesel engines, including the newest from Mercedes have the DPF mounted right on the engine exhaust so it gets hot enough for passive regeneration.

Let's hear from some Sprinter gurus.

Re: Gurus ONLY Educate me about passive regenerations.

PASSIVE REGENERATION:

• Passive regeneration occurs when the exhaust temperatures are naturally high enough (no additional heat is needed from the DOC) to oxidize the soot in the DPF faster than it is collected.
• Passive regeneration typically occurs when the temperature of the DPF is above 572°F (300°C). This occurs during highway driving or when driving with heavy loads.
• Since passive regeneration occurs naturally, it is considered to be normal engine operation. No fuel is added to the exhaust stream during passive regeneration.

http://www.nissantechnicianinfo.mob...vember_Issue_4/Diesel_Particulate_Filter.html

I suppose you could start with the basics. Terminology is a good starting point. So here's a few articles that define active and passive and manual regeneration.

https://www.vehicleservicepros.com/...cle/12182599/dpf-regeneration-modes-explained
https://www.perkins.com/en_GB/produ...missions-technology/passive-regeneration.html
https://www.dieselnet.com/tech/dpf_sys.php
https://www.turbodieselregister.com/threads/passive-regeneration.260723/ (take a look at the third post in the thread)
https://www.knowyourparts.com/technical-resources/diesel-engines/diesel-particulate-filter/
https://en.wikipedia.org/wiki/Diesel_particulate_filter
https://www.fullbay.com/diesel-particulate-filter-dpf-regen/

That should do for a start. Having read all of these links (at least the relevant parts), here's my own description.

The first thing to keep aware of is that the terms "active" and "passive" have to be thought of in terms of what the engine is doing to accomplish the regen. They do NOT relate to what any person has to do.

Passive systems regen - burn off accumulated particulates - in the normal course of operation. The whole system is designed in such a way that the DPF gets hot enough on it's own to burn (technically, oxidize) the trapped particulates. In a vehicle, this might be accomplished by locating the DPF close to the engine so that it is not cooled by airflow around the vehicle, or by using a catalyst so that lower temperatures are adequate for oxidation to occur.

Active regen means that the engine management computer has to create the hot conditions in the DPF so that the particulates can oxidize. This can be done through electric heating or by injecting additional fuel into the exhaust stream to burn there and increase exhaust temperatures.

Manual or stationery regen requires human intervention. Some machinery will prompt the operator to take some action to begin a regen. On vehicles, this may require attaching a diagnostic computer to begin the manual regen.

Now let's apply this to Sprinters. From what I have read, Sprinters are not designed with a passive regen system. They have active and manual systems for a regen. The active system operates via various sensors connected to the engine and transmission control modules. When conditions are right, the Sprinter will inject additional fuel during the exhaust stroke to burn in the exhaust system and raise the temperature in the DPF. And a regen can be activated while the vehicle is in the shop via the Xentry diagnostic system (and possibly other third party diagnostic systems).

Now I realize this all fails your requirement for official Mercedes documentation. That's partly because Mercedes doesn't publish much information for general consumer use. Their general operating philosophy is that end-users don't need to know this stuff. It's only for trained technicians and is likely subject to some non-disclosure agreements. So it's hard or impossible to find this kind of technical design information. If that means I've wasted my time, so be it.

I still learned something by going through the process of attempting to answer your question, so I don't consider it a waste of time.

The key info was in one of PTHELAND's links:

"Diesel particulate matter burns when temperatures above 600 degrees Celsius are attained."

The DPF on a Sprinter never gets close to 600C until fuel is added during a regeneration cycle. I monitor the temps with my UltraGauge.

Re: Gurus ONLY Educate me about passive regenerations.

CJPJ said:

PASSIVE REGENERATION:

• Passive regeneration occurs when the exhaust temperatures are naturally high enough (no additional heat is needed from the DOC) to oxidize the soot in the DPF faster than it is collected.
• Passive regeneration typically occurs when the temperature of the DPF is above 572°F (300°C). This occurs during highway driving or when driving with heavy loads.
• Since passive regeneration occurs naturally, it is considered to be normal engine operation. No fuel is added to the exhaust stream during passive regeneration.

http://www.nissantechnicianinfo.mob...vember_Issue_4/Diesel_Particulate_Filter.html

Click to expand...

This interesting. So, 572°F applies to the Sprinter as well???

Re: Gurus ONLY Educate me about passive regenerations.

CJPJ said:

PASSIVE REGENERATION:

• Passive regeneration occurs when the exhaust temperatures are naturally high enough (no additional heat is needed from the DOC) to oxidize the soot in the DPF faster than it is collected.
• Passive regeneration typically occurs when the temperature of the DPF is above 572°F (300°C). This occurs during highway driving or when driving with heavy loads.
• Since passive regeneration occurs naturally, it is considered to be normal engine operation. No fuel is added to the exhaust stream during passive regeneration.

http://www.nissantechnicianinfo.mob...vember_Issue_4/Diesel_Particulate_Filter.html

Click to expand...

You monitor your temps, what do you normally run while highway driving and did insulating your DPF increase the temperatures?

Re: Gurus ONLY Educate me about passive regenerations.

Bobnoxious said:

You monitor your temps, what do you normally run while highway driving

Click to expand...

Never monitored the DPF temps, ..I do have the scangage II but never set it to exhaust temp.

and did insulating your DPF increase the temperatures?

Click to expand...

Estimate it certainly would! Apparently around 450°f oxidation starts, 572° as per graphic the rate becomes more efficient with the increased temperatures

Re: Gurus ONLY Educate me about passive regenerations.

CJPJ said:

Never monitored the DPF temps, ..I do have the scangage II but never set it to exhaust temp.
Estimate it certainly would! Apparently around 450°f oxidation starts, 572° as per graphic the rate becomes more efficient with the increased temperatures

Click to expand...

Everything I've read indicates it takes a catalyst to get passive regeneration at those low temps.

https://www.ctscorp.com/products/se...lter-dpf-knowledge-base/basics-dpf-operation/

http://www.cumminshub.com/emissions.html

https://www.energy.gov/sites/prod/files/2014/03/f9/2004_deer_chatterjee.pdf

Re: Gurus ONLY Educate me about passive regenerations.

Boxster1971 said:

Everything I've read indicates it takes a catalyst to get passive regeneration at those low temps.

https://www.ctscorp.com/products/se...lter-dpf-knowledge-base/basics-dpf-operation/

http://www.cumminshub.com/emissions.html

https://www.energy.gov/sites/prod/files/2014/03/f9/2004_deer_chatterjee.pdf

Click to expand...

How about This:
https://www.slideshare.net/mobile/KamalVora1/dr-vora-ppt-chapter-5-diesel-aftertreatment

New cat and dpf on a 07 NCV3 I typically see 700F on a fully loaded van Going up a hill 73 F ambient going 65 mph dpf diffental at 35-55. Going down the hill I’ll se the temps drop to 400 F
Very important to see high egr cooler temp sensor reading ? Do you know why ? Because if the egr cooler solenoid doesn’t bypass cooler ..all the extra fuel used for regenerate will
Plug the cooler with soot

Attaching two documents from Mercedes about the V-6 diesel exhaust after treatment including the DPF.

In the first document a description of the DPF indicates in order to burn off the soot particles, temperatures of over 600 degC are required. It also states that these temperatures are not reached during normal operation of the diesel engine.

The second document describes the function sequence for DPF and the regeneration cycle.

enjoy,

on my 2015, I can watch the DPF soot load estimate using scangauge II

while in general, the value increases while driving, and decreases during DPF regeneration events, it goes up and down, depending on driving conditions. this downward-trend during driving (outside regeneration) is either passive regeneration, or re-ordering of soot within the DPF which allows reduction in differential pressure (which is used in estimation of the DPF soot load)

I recall we had this passive regen discussion 7-10 years back.............I think the general consensus was Sprinters don’t passive regen. They might produce less soot at high speed high loads as they run hotter exhaust temps ? I have noticed longer intervals between regen when running fast and loaded.


Here’s short discussion from 2010:
https://sprinter-source.com/forum/showthread.php?t=11929&highlight=Passive+regen&page=2

Obviously since then we all learned to watch for regen with the scan gauge. Before that many of us never noticed regen activity.

Boxster1971 said:

Attaching two documents from Mercedes about the V-6 diesel exhaust after treatment including the DPF.

In the first document a description of the DPF indicates in order to burn off the soot particles, temperatures of over 600 degC are required. It also states that these temperatures are not reached during normal operation of the diesel engine.

The second document describes the function sequence for DPF and the regeneration cycle.

enjoy,

Click to expand...

Interpretation of the temperature required to burn off, - meaning restore to clean. .. a crossover regenerate sweet spot is required. .. Doesn't spite the fact that cleaning oxidation starts earlier.

mikeme said:

on my 2015, I can watch the DPF soot load estimate using scangauge II

while in general, the value increases while driving, and decreases during DPF regeneration events, it goes up and down, depending on driving conditions. this downward-trend during driving (outside regeneration) is either passive regeneration, or re-ordering of soot within the DPF which allows reduction in differential pressure (which is used in estimation of the DPF soot load)

Click to expand...

Good info. Is the DPF soot load estimate a standard parameter on a ScanGauge II? Or did you have to program it in?

The Mercedes documents I posted indicate 99% soot burn during fuel induced regeneration. Your observation would indicate some level of passive soot burning, but not enough to keep up with eventual soot load.

That info helps explain the varying mileage I've observed between regenerations when exhaust temp rises above 1200 degF.

DPF parameters are a custom X gauge the user can program into a scangauge.

recently the engineer at scangauge developed and posted a bunch of them.

https://www.scangauge.com/x-gauge-commands/mercedes-sprinter-w-3-0l-diesel/

and

https://www.scangauge.com/x-gauge-commands/2014-mercedes-sprinter-2-1l-diesel/

PFL is the gauge I am referring to.

The transmission fluid temp is also a handy one to have.

Thank you for the education. If the 572 degree regeneration temp value is correct, it appears Sprinters can passively regenerate occasionally.

I noticed DPF temps occasionally reach 572 degrees and a little beyond needed. However, the majority of the time, temps are well below 572.