Regen

[jasmith348]

I forgot to mention, I’ve been timing my regeneration and it takes around 13-15 minutes to complete a regeneration.

I'd say my active regens take in the 15-20 min range. The dealer replaced all of the injectors last August and that really sped the active regens up. Got a new DPF and several other things last June. It seems to take the truck about 20-30 mins on the interstate to start passively regenning.

 

[AH64ID]

15-20 minutes for a active regeneration cycle is normal, under most situations.

That’s what I’ve found for time based regens, 3 of my 4 soot based regens took much longer. The only soot based regen that didn’t take longer occurred with my 5th wheel hooked up just as I got to a 7% grade. (I wasn’t able to get enough passive regen towing that morning before it tripped a soot load based regen).

 

[mbarber84]

As I posted yesterday 75 mph is fast enough to not load the DPF with soot, but also not fast enough empty for a rapid passive regen… of course that all depends on winds, temps, and grade.

What I’ve noticed by monitoring EGT3, DPF outlet, is this

Above 22 mpg: no passive regen
18-22 mpg: net neutral, no real soot production or passive regen
Below 18 mpg: passive regen
Below 12 mpg: rapid passive regen

That’s all average mileage, not instant. At 75 I’m 18-20 mpg and it takes forever for soot loading to reduce once it’s built up to 12.5-25%.

It’s interesting to see your numbers. My truck spends the majority of its time on the highway and sees 75mph religiously via cruise control. The best mpg I’m able to achieve consistently is roughly 14-15mpg at that speed. Thats a CC LB 3500 HO DRW with the 3.73 axle. Maybe the SRW are a little more fuel efficient due to less weight and better aerodynamics

 

[jenninr]

This is a red flag.

A truck with 17k behind it constantly should see nothing but the 24 hour timer-based regeneration cycles. Especially if that truck is seeing highway operation for moderate lengths of time.

Start monitoring your oil level and oil condition
Check the engine air filter for right one
Inspect boost tubes / charge pipes and boots for leaks

I forgot to mention that the truck is making oil. It has the original Mopar filter in it.

 

[Units]

As I posted yesterday 75 mph is fast enough to not load the DPF with soot, but also not fast enough empty for a rapid passive regen… of course that all depends on winds, temps, and grade.

What I’ve noticed by monitoring EGT3, DPF outlet, is this

Above 22 mpg: no passive regen
18-22 mpg: net neutral, no real soot production or passive regen
Below 18 mpg: passive regen
Below 12 mpg: rapid passive regen

That’s all average mileage, not instant. At 75 I’m 18-20 mpg and it takes forever for soot loading to reduce once it’s built up to 12.5-25%.

Do you notice exhaust temps go up at say 80 mph? I thought about that but I don’t have a way to monitor it.

 

[AH64ID]

It’s interesting to see your numbers. My truck spends the majority of its time on the highway and sees 75mph religiously via cruise control. The best mpg I’m able to achieve consistently is roughly 14-15mpg at that speed. Thats a CC LB 3500 HO DRW with the 3.73 axle. Maybe the SRW are a little more fuel efficient due to less weight and better aerodynamics

Yeah the DRW will make a difference.


The other thing I’ve noticed with the DPF gauge, and why I think there is a programming issue, is that my gauge will sometimes register 12.5% or even 25% and then drop back down rapidly with a quick merging in traffic or passing without the DPF being hot enough for passive regen. The truck isn’t estimated soot loading accurately all the time.

Do you notice exhaust temps go up at say 80 mph? I thought about that but I don’t have a way to monitor that.

Yes, the faster you drive the higher the EGT’s and thus the hotter the DPF. That’s what I’ve correlated fuel economy to.

Above 22 mpg EGT’s are below 600°
Below 18 mpg EGT’s are above 650°
Below 12 mpg’s EGT’s are above 700°

The DPF needs to be at ~650° to begin passive regen. When EGT1 is above 650° and EGT3 (DPF outlet) is above 600° I’ll start to see a little passive regen.

 

[jasmith348]

It’s interesting to see your numbers. My truck spends the majority of its time on the highway and sees 75mph religiously via cruise control. The best mpg I’m able to achieve consistently is roughly 14-15mpg at that speed. Thats a CC LB 3500 HO DRW with the 3.73 axle. Maybe the SRW are a little more fuel efficient due to less weight and better aerodynamics

My truck really likes to get real close to 80mph before the passive regen kicks in. Thats on a generally flat interstate.

 

[jasmith348]

Yeah the DRW will make a difference.


The other thing I’ve noticed with the DPF gauge, and why I think there is a programming issue, is that my gauge will sometimes register 12.5% or even 25% and then drop back down rapidly with a quick merging in traffic or passing without the DPF being hot enough for passive regen. The truck isn’t estimated soot loading accurately all the time.




Yes, the faster you drive the higher the EGT’s and thus the hotter the DPF. That’s what I’ve correlated fuel economy to.

Above 22 mpg EGT’s are below 600°
Below 18 mpg EGT’s are above 650°
Below 12 mpg’s EGT’s are above 700°

The DPF needs to be at ~650° to begin passive regen. When EGT1 is above 650° and EGT3 (DPF outlet) is above 600° I’ll start to see a little passive regen.

I personally think the DPF gauge software/system is at least a little screwy. There's just no way one of these trucks can load up to 25% on that gauge in 10-12 miles of driving, as mine has done. Or if it can do that, then the gauge shouldnt read 0% after a regen. Either the low end or upper end reading has to be wrong.

 

[AH64ID]

I personally think the DPF gauge software/system is at least a little screwy. There's just no way one of these trucks can load up to 25% on that gauge in 10-12 miles of driving, as mine has done. Or if it can do that, then the gauge shouldnt read 0% after a regen. Either the low end or upper end reading has to be wrong.

It is a little screwy, mostly at low rpm, low load, and low temps from what I can tell.

The PID for regen will show you residual soot/ash after a regen and that’s a good way to tell if your regen was effective or not.

 

[Finn5033]

I have a 22 that was a leftover I bought new from a dealer last August, it had 18 miles on it. This is my first HD diesel truck and I bought it just because I’ve always wanted one. I was aware of the issues with emissions equipment on the newer diesel trucks and always told myself if I ever started having problems and it was constantly at the dealership I’d just dump it and go back to an HD gas truck.

Having said that I use mine as my daily driver which is 80 miles round trip to work mostly freeway, and then use it to tow our RV / Fish house on 10 or so trips a year. So I figured the way I use it would help keep the DPF clean and not be an issue. I only have 14,000 miles on it but so far my truck only regens at the 24hr cycle and I’ve had no other issues or check engine lights.

I feel for you guys that are having these issues. Now that I’ve read about these problems, if I start experiencing this I’m getting rid of mine right away. Unless they get this figured out that is. I had already decided that if I was out of warranty I’d just delete but I’m not doing that to a truck that’s still under warranty. I hope they get this figured out because I really like my truck, but this is making me nervous that it’s only a matter of time before mine is next.

 

[jasmith348]

It is a little screwy, mostly at low rpm, low load, and low temps from what I can tell.

The PID for regen will show you residual soot/ash after a regen and that’s a good way to tell if your regen was effective or not.

My info screen always goes down to 0% after an active regen. I can also get it there after about 60 mins total of interstate driving assumning it starts around thr 37.5% mark.

Also, I think you are on to something with the low temp issue. I posted this once before in the long regen thread, but I go up a 2 mile or so hill at about 5% grade within 5 miles of leaving my house to get to the office. The DPF gauge absolutely hates that. I can park the truck in the evening after having just completed an active regen (to 0%) and I've seen the DPF gauge read 12.5 or even 25% after going up that hill in the morning.

I know the truck is not really warm/hot, but that hill absolutely loads up the DPF, if the gauge is to be beleived.

 

[Units]

Well, I guess it’s 80mph on the interstate for a while. @AH64ID, I’ve noticed the same thing on my DPF gauge. It seems to jump up pretty quickly from say 15% to 25% and I really haven’t been driving long enough for so much soot loading. After my commute and I shut down and start back up it drops back down and it will jump right back up to 25% real quick.

 

[jasmith348]

I have a 22 that was a leftover I bought new from a dealer last August, it had 18 miles on it. This is my first HD diesel truck and I bought it just because I’ve always wanted one. I was aware of the issues with emissions equipment on the newer diesel trucks and always told myself if I ever started having problems and it was constantly at the dealership I’d just dump it and go back to an HD gas truck.

Having said that I use mine as my daily driver which is 80 miles round trip to work mostly freeway, and then use it to tow our RV / Fish house on 10 or so trips a year. So I figured the way I use it would help keep the DPF clean and not be an issue. I only have 14,000 miles on it but so far my truck only regens at the 24hr cycle and I’ve had no other issues or check engine lights.

I feel for you guys that are having these issues. Now that I’ve read about these problems, if I start experiencing this I’m getting rid of mine right away. Unless they get this figured out that is. I had already decided that if I was out of warranty I’d just delete but I’m not doing that to a truck that’s still under warranty. I hope they get this figured out because I really like my truck, but this is making me nervous that it’s only a matter of time before mine is next.

I think the 80 miles of interstate driving will help keep any issues at bay. Though there are still some of these trucks that develop issues even if they truly work for a living, so who knows. Ram certainly doesnt seem to know.

 

[jasmith348]

Well, I guess it’s 80mph on the interstate for a while. @AH64ID, I’ve noticed the same thing on my DPF gauge. It seems to jump up pretty quickly from say 15% to 25% and I really haven’t been driving long enough for so much soot loading. After my commute and I shut down and start back up it drops back down and it will jump right back up to 25% real quick.

Yeah my gauge has done something similar. That leads me to wonder if the gauge/software is triggering all of these active regens when the filter doesnt actually need them? The head tech at my local dealership said something along these lines yesterday.

 

[AH64ID]

Yeah my gauge has done something similar. That leads me to wonder if the gauge/software is triggering all of these active regens when the filter doesnt actually need them? The head tech at my local dealership said something along these lines yesterday.

When my gauges bounces around oddly the DPF Regen PID doesn’t react the same, it’s still moving around but not quite the same.

 

[mbarber84]

When my gauges bounces around oddly the DPF Regen PID doesn’t react the same, it’s still moving around but not quite the same.

Could this be due to the thresholds they have programmed? Not sure how to explain, but the gauge may sit at “zero” for a while but what’s the threshold to tip it over to 12.5% then 25% etc. Their choice to block off the output data in chunks makes little sense, and leaves room for “leeway” in the reading and subsequent output to the gauge itself. There’s also the consideration of temperature & pressure fluctuations which may also contribute to variations in the reading.

This would be so much more easy to understand and diagnose if we had full access to the intrinsic information and programming data for what drives all of these systems….

 

[firemansdiesel]

B20R80?

Yes. Here atleast in California it’s usually 80/20 mix. Stickered on the pump.

 

[AH64ID]

Could this be due to the thresholds they have programmed? Not sure how to explain, but the gauge may sit at “zero” for a while but what’s the threshold to tip it over to 12.5% then 25% etc. Their choice to block off the output data in chunks makes little sense, and leaves room for “leeway” in the reading and subsequent output to the gauge itself. There’s also the consideration of temperature & pressure fluctuations which may also contribute to variations in the reading.

This would be so much more easy to understand and diagnose if we had full access to the intrinsic information and programming data for what drives all of these systems….

That’s the part I think is a programming error, with both the gauge and what the truck uses to determine soot loading.

 

[mbarber84]

Yes. Here atleast in California it’s usually 80/20 mix. Stickered on the pump.

Not a diesel-friendly place. In all sorts of ways.

 

[AZCummins]

This has been an interesting read. I have been obsessively trying to get an idea of how my regens are performing for the past couple of weeks to get an idea of if I need to start preparing myself for an issue. 2020 2500 with 54K miles and the last two periods between regens have have been:

333.7 Miles
9 Hours 26 Minutes
(mostly short trips with a couple moderate highway trips)

256.1 Miles
7 hours 38 minutes
(All short trips)

I thought these seem pretty short intervals, but this truck gets a lot of short empty trips. Lats time I drove up through the Mountains on a 2 1/2 hour trip and then back a couple days later it did not regen once and the passive regen seemed very effective.

I think based on everything I am reading in here I am going to count this as a win for 54K miles and keep my fingers crossed it stays around this level.