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Significant Change in the Frequency of Active Regens

mbarber84

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I tried to search prior to posting, but "frequency" of regen is bringing up more content related to DTC's. This did not match my scenario so here we are:

My Truck: 2022 3500 HO CCLB DRW 3.73
Current Odometer: 23,950 miles

Background Information:
I just completed my second fluid and filter service on December 30th 2022 with 23,052 miles on the odometer. As per my usual routine I changed engine oil (Amsoil Signature 10W-30 Diesel) and filter (Fleetguard LF16035), both fuel filters (Fleetguard FS53000 and Mopar 68436631AA), and the engine and cabin air filters. This service was previously completed at 11,728 miles. Total mileage elapsed between services comes out to 11,324 miles. The only difference between the previous service and the one I just completed was a change in the engine air filter (The previous air filter was a Napa Gold #6930 of the older design, which contained the orange foam and yellow filtration media WITHOUT the glue strips. The new filter was a MOPAR 68517554AA) and the addition of Hotshots Secret Diesel Extreme in to a full tank of fuel (50 gallons). It should be noted that I also have hotshots EDT in the fuel. In terms of how I use my truck, it is my daily driver used for both commutes to and from work as well as for farm-related work and towing. Drive cycles consist of primarily highway travel where speeds are usually 65-75 mph for lengths ranging from 20 minutes to 2 hours, with some lower speed local driving mixed in. When operating below 50mph, I usually use the ERS to limit the truck to 4th or 5th gear depending on road conditions in order to keep rpm`s up and reduce some gear searching / lugging. I do my best to limit idle time, allowing the truck a few minutes to warm up before driving in cooler temps and shutting if off during fueling and other situations where the truck needn't continue running.

Observation:
I seem to be noticing a significant reduction in the number of active (aka "automatic") regeneration cycles compared to that of the previous oil change interval. Prior to this most recent service, I seem to remember the truck performing an active regen cycle regularly, usually initiating when my DPF hit about 25% full. Active regen cycles were regularly noticed and seemed to be on a fairly frequent basis. This frequency remained rather constant and consistent throughout the 11,728 miles traveled. My DPF gauge almost never exceeded 25% full at any time, with an occasional higher reading of up to 30% or so. The frequency of the regen cycles, coupled with the highway drive cycles I completed seemed to "keep the DPF at bay" so to speak. At no point did the truck ever show any signs of a malfunction, and no MIL`s or DTC`s were present. Fast forward to today: I have traveled just shy of 900 miles and encompassed 21 days since the last service was completed. During this time, the truck has NOT conducted an active regeneration cycle. Drive cycles have remained primarily the same with no significant changes in how the truck is used or driven. The DPF gauge has been slowly creeping up. I have noted some reduction in the soot reading over this time period which, I can attribute to passive regeneration occurring during highway driving. That being said, however, the gauge is ultimately still increasing overall. As of right now, the DPF gauge is reading very close to 50% full. Based on my previous experience with active regen cycles over the course of the last service interval, I feel as though the truck "should" or "would" have completed one automatic cycle by now. I have also noticed some erratic behavior in regard to the DPF gauge itself. In one such instance, I drove the truck approximately 2 hours steady at highway speed averaging 70-72mph. During this trip, the DPF gauge moved from about 30-35% full at the beginning of the trip, to about 25% at the end of the trip. On my 15 minute highway commute to work the following morning, the gauge started out at 25% where it left off the previous day, and by the time I reached work fifteen minutes later, the gauge was reading practically zero. I found myself struggling to understand how a 2 hour highway drive could result in a reduction of only 5-10% and yet a fifteen minute short highway commute resulted in a reduction of 20% or more.

Questions / Hypotheses:
1. Why isn't the truck actively regenerating at the same frequency it was prior to the most recent service given that the drive cycles are pretty much identical?
2. If the truck was regenerating more frequently during the previous service interval, what was causing that? Was it a result of an inferior engine air filter? If the Napa / Wix was inferior, why did it not trigger a MIL / DTC?
3. What effect would the Hotshot EDT / Extreme additives have on the frequency of regeneration?

At this point, I am hopeful that I`ll see an active regen cycle soon. IF that does happen, I plan to begin tracking those more intentionally. I regret that I didn't start doing that during the previous service interval as I would have some concrete data to draw conclusions from. Ultimately this will be a learning lesson in many ways. I`m still learning the ins and outs of this truck even a year in to it`s ownership. I can say with certainty this is a different animal than my previous 2017 3500 HO. I like the idea of having the DPF gauge to monitor, however I am beginning to question the functionality and accuracy of it. It does not seem to provide timely information or feedback, the moves that it makes do not seem to coincide with what I know and expect of the emissions system operation, and I am curious as to the sensitivity of the emission system over my previous truck. I told a friend of mine the other day, as we were discussing the same issue I`m now sharing with you, that I sometimes look back at the my 2017 truck and think about the fact that I did not have a DPF gauge to monitor. I simply drove the truck as I needed to, and the emission system gave me almost 80,000 trouble-free miles before I sold it to fund this new one. I guess the old saying "Ignorance is bliss" has some merit.

I`ll keep driving and monitoring for now, with the hope I`ll have an automatic regen cycle start soon. I don't have any trailering to do in the near future so there wont be much opportunity for passive regen to clean it all out. I`m in a good position to see if this thing is going to kick in soon. In the meantime, I would be interested to hear your thoughts and input on all of the above.
 
This is purely conjecture, but I could speculate on it being any number of things.

1.) If I remember correctly one of Diesel Extreme's mechanisms of cleaning is to help increase EGT in the DOC/DPF. If it's working as intended you could be seeing a cleaning effect if were on the edge of attaining passive regens with your normal use. Again speculation
2.) This could very well be an airfilter thing. I've heard several 1st and 2nd hand accounts of installing the S&B Filters intake and seeing less regens as a result. All things being equal you want a lean burn to cut down on soot formation and it could be under transient conditions that certain filters aren't restrictive enough to cause a code, but do throw the engine out of its efficiency curve. These transient conditions will happen a lot more with city/daily driving than straight highway driving. Also speculation
3.) From what I've seen on my SO and other SO's/HO's in the friends/family, using HSS does help a bit on regens. I've noticed running EDT every fill up (half rate where I can get TXLED Diesel and full/perf rate where it's the min 40 cetane stuff) cuts down quite a bit on DPF loading when I do daily drive my truck. When its just being run straight highway for long trips up to other parts of the state it doesn't seem to matter as much on the DPF. Outside of that EDT seems to help with engine reponse/smoothness when boosting up the cheap truck stop 40 centane stuff. What I've noticed from the Diesel Extreme is that it seems to help most with folks who idle, city drive, or short trip more than folks who are always running hot enough EGTs to passive regen often. There have been a couple of forum posts about Diesel Extreme helping with problematic, frequent regens.


I've noticed that my DPF gauge can be iffy from time to time so instead I just watch my DPF Diff Pressure on one of my Banks iDashes.
 
To confirm you are seeing the active regen in progress message on the DPF page? Or just going by a reduction in DPF percent?

Record engine hours at the regen. The next regen should occur 24 hours later. If it occurs before that then your driving style isn’t conducive to passive regen.

I’ll sometimes go around 1000 miles between regens, that’s only an average of 42 mph. Some times I go a few hundred miles if I’m in the woods.
 
This is purely conjecture, but I could speculate on it being any number of things.

1.) If I remember correctly one of Diesel Extreme's mechanisms of cleaning is to help increase EGT in the DOC/DPF. If it's working as intended you could be seeing a cleaning effect if were on the edge of attaining passive regens with your normal use. Again speculation
2.) This could very well be an airfilter thing. I've heard several 1st and 2nd hand accounts of installing the S&B Filters intake and seeing less regens as a result. All things being equal you want a lean burn to cut down on soot formation and it could be under transient conditions that certain filters aren't restrictive enough to cause a code, but do throw the engine out of its efficiency curve. These transient conditions will happen a lot more with city/daily driving than straight highway driving. Also speculation
3.) From what I've seen on my SO and other SO's/HO's in the friends/family, using HSS does help a bit on regens. I've noticed running EDT every fill up (half rate where I can get TXLED Diesel and full/perf rate where it's the min 40 cetane stuff) cuts down quite a bit on DPF loading when I do daily drive my truck. When its just being run straight highway for long trips up to other parts of the state it doesn't seem to matter as much on the DPF. Outside of that EDT seems to help with engine reponse/smoothness when boosting up the cheap truck stop 40 centane stuff. What I've noticed from the Diesel Extreme is that it seems to help most with folks who idle, city drive, or short trip more than folks who are always running hot enough EGTs to passive regen often. There have been a couple of forum posts about Diesel Extreme helping with problematic, frequent regens.


I've noticed that my DPF gauge can be iffy from time to time so instead I just watch my DPF Diff Pressure on one of my Banks iDashes.
That all tracks with my suspicions as well.
I’m going to keep monitoring for now and see how this progresses. I’m still early in this service interval so lots of time left to watch for patterns and see how these items help
 
To confirm you are seeing the active regen in progress message on the DPF page? Or just going by a reduction in DPF percent?

Record engine hours at the regen. The next regen should occur 24 hours later. If it occurs before that then your driving style isn’t conducive to passive regen.

I’ll sometimes go around 1000 miles between regens, that’s only an average of 42 mph. Some times I go a few hundred miles if I’m in the woods.
Correct. I am watching for the message on the DPF screen in order to confirm an active regen is in progress. I also monitor the reading in the gauge to determine how much soot is removed during a passive regen while I’m on the interstate and no active regen occurs during the trip.

The truck actually went into active regen tonight for the first time since I completed the last service interval. I took some pictures of the message when it first appeared as well as when the message cleared and the DPF returned to zero. That way I have a time stamp on each and can calculate how long it took. I was on the interstate and continued to drive in order to let the cycle finish. I can also see how many hours and miles have elapsed in order to track the frequency.

As always, I really appreciate your input
 
Correct. I am watching for the message on the DPF screen in order to confirm an active regen is in progress. I also monitor the reading in the gauge to determine how much soot is removed during a passive regen while I’m on the interstate and no active regen occurs during the trip.

The truck actually went into active regen tonight for the first time since I completed the last service interval. I took some pictures of the message when it first appeared as well as when the message cleared and the DPF returned to zero. That way I have a time stamp on each and can calculate how long it took. I was on the interstate and continued to drive in order to let the cycle finish. I can also see how many hours and miles have elapsed in order to track the frequency.

As always, I really appreciate your input

With what you have described it seems like previously you were sooting up and requiring a regen before the 24 hour mark… or you drove more than you think.

What you are describing as occurring since the last service interval seems normal, and how mine operates.
 
With what you have described it seems like previously you were sooting up and requiring a regen before the 24 hour mark… or you drove more than you thing.

What you are describing as occurring since the last service interval seems normal, and how mine operates.
I agree completely.

The only thing I`m not sure of is the reason behind it. Either it was:
A) The Napa air filter was more restrictive than the current OEM one, but not enough to trigger a code
B) I had an injector, or injectors, that needed "flushed" out and the HSS Extreme did the trick
C) The EDT improved the efficiency of the combustion
D) A combination of the above

I am very confident that the drive cycles accumulated this time were extremely close to previous cycles

I`ll be curious to see how the truck performs from this point moving forward.

This most recent Active regeneration cycle took exactly 20 mins to complete, running the truck unloaded on the highway at 72-75 mph in 6th gear (puts my RPM's between 1900-2000)
The pre-cycle DPF reading was just shy of 50% full and after the 20 minute constant run, it reached 0%.
Engine hours at the time the cycle initiated were 762 and mileage was 23,968 (1/20/2023)
Fuel would still have HSS EDT and EXTREME in it at this point, but not absolutely certain of concentration as I topped off recently and didnt have my EDT bottle with me.

I will monitor the next cycle and report back.
 
E) none of the above, it was more likely driving style.

If B or C were the case at 24K miles I’d be shocked, unless you use crap fuel.

Run the air filters longer. Stick with OEM ones.

This is my log for reference.

34CC0311-A932-4741-8914-FC5A77C10EC7.jpeg

The minor variance from 24 hours is due to how the dash reads. Total hours is just idle plus drive, so you could have 4.9 idle and 19.1 drive but only show 23 and really be at 24.

I record the hours at completion, and the one that took 26 hours took multiple drive cycles to compete based on the low speed.

You can see that after 10 regens my average is 24.5 hours, which is right on track since the 24 hour clock restarts at the completion of each regen.
 
I dont think it was fuel related. I fill up at the same stations 90%+ of the time and they are all new Sheetz locations that move a lot of fuel.
All of my filters have looked clean with no sign of contamination the last two services (chassis mounted rear filter was dark grey / black but I attribute that to the asphaltenes)
Truck has never appeared low on power or struggling.

We`ll give it time to see how things are moving forward but there is unquestionably a difference after this most recent service.

Thanks for your input I appreciate it!
 
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