2019 Cummins Rough & Tumble Idle After Morning Start Up. What could be wrong?

[nlambert182]

I don't know what it is. There are a couple of different potential failure modes.

 

[crash68]

It's empty

So, it could be the DPF after all?

Last trip it did a passive regen

If you mean just the truck by saying empty, then the truck didn't passive regen. It was most likely an active regen. For the truck to passive regen, you need to be working it hard enough that the exhaust get hot enough to clean the DPF without having to actively inject fuel to burn the soot off. Typically for soot to burn off the DPF temperature needs to be above 1000°F
For the Cummins you probably need to be pulling a decent grade with a trailer weighing at least 10K-12K lbs.

 

[Goose55]

If you mean just the truck by saying empty, then the truck didn't passive regen. It was most likely an active regen. For the truck to passive regen, you need to be working it hard enough that the exhaust get hot enough to clean the DPF without having to actively inject fuel to burn the soot off. Typically for soot to burn off the DPF temperature needs to be above 1000°F
For the Cummins you probably need to be pulling a decent grade with a trailer weighing at least 10K-12K lbs.

The dealership where I bought the truck, new, wants to buy it back from me. I think maybe I should take them up on that. What do you think, Mr. Lambert? I've had my fun with it.

I don't need this much of a truck to go fly fishing in Utah. My dad always said my eyes were bigger than my head.

 

[06 Dodge]

If you mean just the truck by saying empty, then the truck didn't passive regen. It was most likely an active regen. For the truck to passive regen, you need to be working it hard enough that the exhaust get hot enough to clean the DPF without having to actively inject fuel to burn the soot off. Typically for soot to burn off the DPF temperature needs to be above 1000°F
For the Cummins you probably need to be pulling a decent grade with a trailer weighing at least 10K-12K lbs.

Going to have to disagree that you need the truck loaded to do a passive regens, I can get my truck to do passive regens with truck empty/no towing of any kind in as little as 30 minutes driving nonstop at speeds above 45 mph, but then I also use a fuel additive that helps with regens...

 

[Goose55]

Going to have to disagree that you need the truck loaded to do a passive regens, I can get my truck to do passive regens with truck empty/no towing of any kind in as little as 30 minutes driving nonstop at speeds above 45 mph, but then I also use a fuel additive that helps with regens...

Please tell me. What is the fuel additive you use that helps with regens?

 

[crash68]

I can get my truck to do passive regens with truck empty/no towing of any kind in as little as 30 minutes driving nonstop at speeds above 45 mph

A passive regen is when the ECM is not making changes in the fuel mapping/timing to elevate the exhaust temperatures to burn of soot. Only way a passive regen happens is with enough load on the engine. Drive on the freeway unloaded and watch the DPF temp (EGT4) itt will probably hovers around 600°. Two ways to get that temperature to go up, either a good load on the engine or an active regen.
I don't even think downshifting and holding close to 3K rpms would generate enough heat.
If Regen is happening at 45 mph I'd be willing to bet that the ECM is changing the fuel map/timing to elevate the DPF temperature, if not you'd wouldn't be able to cruise at 70 mph for hours without being in a state of constant regen which eventually would shorten the DPF life

 

[nlambert182]

Well, depending on the type of roads and elevation and driving style you "could" potentially have a passive regen without a load, but it's not typical. If you can get and keep the exhaust temps above 600 degrees for an extended period of time it will be in passive regen. That's not impossible to do.

If you're cruising at 70 mph down a flat interstate, likely not.

 

[nlambert182]

The dealership where I bought the truck, new, wants to buy it back from me. I think maybe I should take them up on that. What do you think, Mr. Lambert? I've had my fun with it.

I don't need this much of a truck to go fly fishing in Utah. My dad always said my eyes were bigger than my head.

Take it.

 

[06 Dodge]

A passive regen is when the ECM is not making changes in the fuel mapping/timing to elevate the exhaust temperatures to burn of soot. Only way a passive regen happens is with enough load on the engine. Drive on the freeway unloaded and watch the DPF temp (EGT4) itt will probably hovers around 600°. Two ways to get that temperature to go up, either a good load on the engine or an active regen.
I don't even think downshifting and holding close to 3K rpms would generate enough heat.
If Regen is happening at 45 mph I'd be willing to bet that the ECM is changing the fuel map/timing to elevate the DPF temperature, if not you'd wouldn't be able to cruise at 70 mph for hours without being in a state of constant regen which eventually would shorten the DPF life

My self don't care how it happens or what the ECU does, but when I see my DPF gauge drop from showing 25% down to zero while driving the truck unloaded too me its a passive regen and have been able to do so regularly since I started using Archoil 6400d & 6500 fuel additives, before I stared to use it I was lucky to drive 300-350 miles between soot loaded regens, now with using Archoil I can go a full 24 hours between regens.. I've also heard that Pittsburgh Power also has a fuel additive that will also help with regens but have not tried it or talked to anyone who has so cant comment on it...

 

[06 Dodge]

Please tell me. What is the fuel additive you use that helps with regens?

I use Archoil 6400d system cleaner, then Archoil 6500 additive in every tank....

 

[Goose55]

I use Archoil 6400d system cleaner, then Archoil 6500 additive in every tank....

This one is endorsed by Cummins but makes no claim to clean the DPF

 

[06 Dodge]

This one is endorsed by Cummins but makes no claim to clean the DPF

View attachment 571934

Watch this U-tube video I found and watched it, I was surprised to hear that the top 2 diesel additives are Archoil and Hot Shot every day additive. FYI Power Service paid Cummins to get there approval to put their name on there bottles just like Valvoline did for there diesel oil, just because it has Cummins name on the bottle does not mean its the best...

The TRUTH About DIESEL ADDITIVES…Scam or Science?

Use code 50FREEDOMWORX to get 50% OFF plus free shipping on your first Factor box at https://bit.ly/4mopMMV !Are Diesel Fuel Additives Actually Effective? Ar...

www.youtube.com

 

[crash68]

My self don't care how it happens or what the ECU does, but when I see my DPF gauge drop from showing 25% down to zero while driving the truck unloaded too me its a passive regen

So your making the assumption it's passive but in reality the ECU is controlling the DPF burnoff. Fuel is injected during the exhaust stroke so the fuel vapors burn and elevate the DPF temps.
Only way to know your doing a passive regen would be to monitor the EGT4 temperature regularly while just driving then comparing that to while loaded. For a passive regen to happen the first four EGT sensors will all be playing with 4 digit temperature readings.
Even as light duty as the EcoD is compared to the Cummins, it takes an 8K load pushing against headwinds while traveling 60-65mph for passive regen to happen.

 

[nlambert182]

Regardless... a passive regen with an empty load IS possible. It just requires certain circumstances. We can't necessarily assume that an active regen is happening just because he's empty. He only needs a steady 600-700 degree EGT over a longer period of time to do a passive regen. Again, not the most commonplace, but I've pushed some pretty high EGTs on hilly sections of interstate.

 

[Goose55]

So your making the assumption it's passive but in reality the ECU is controlling the DPF burnoff. Fuel is injected during the exhaust stroke so the fuel vapors burn and elevate the DPF temps.
Only way to know your doing a passive regen would be to monitor the EGT4 temperature regularly while just driving then comparing that to while loaded. For a passive regen to happen the first four EGT sensors will all be playing with 4 digit temperature readings.
Even as light duty as the EcoD is compared to the Cummins, it takes an 8K load pushing against headwinds while traveling 60-65mph for passive regen to happen.

It's marvelous technology but some some, a head ache.

 

[Goose55]

My self don't care how it happens or what the ECU does, but when I see my DPF gauge drop from showing 25% down to zero while driving the truck unloaded too me its a passive regen and have been able to do so regularly since I started using Archoil 6400d & 6500 fuel additives, before I stared to use it I was lucky to drive 300-350 miles between soot loaded regens, now with using Archoil I can go a full 24 hours between regens.. I've also heard that Pittsburgh Power also has a fuel additive that will also help with regens but have not tried it or talked to anyone who has so cant comment on it...

This is what my premise is. The DPF gauge dropped and there had been no announcement about an active regen in process. It was a passive regen.

 

[nlambert182]

There are 2 ways that an active regen occurs.

1) Every 24 hrs from the last regen.
2) Once the DPF soot level raises above 80% full.

If it's a scheduled regen, it will not display in the EVIC. It will only display if it's a regen based on the soot level.

If it isn't one of those 2, it's a passive regen. A passive regen basically just helps keep it clean and extends the amount of time between an active regen based on soot level. It still doesn't stop the scheduled regens.

 

[06 Dodge]

So your making the assumption it's passive but in reality the ECU is controlling the DPF burnoff. Fuel is injected during the exhaust stroke so the fuel vapors burn and elevate the DPF temps.
Only way to know your doing a passive regen would be to monitor the EGT4 temperature regularly while just driving then comparing that to while loaded. For a passive regen to happen the first four EGT sensors will all be playing with 4 digit temperature readings.
Even as light duty as the EcoD is compared to the Cummins, it takes an 8K load pushing against headwinds while traveling 60-65mph for passive regen to happen.

Don't know how your Eco emission system works but in my truck it will show on EVIC if my truck goes in to a regen mode, be it soot load or the 24 hour regen ( I have many different photos over the past years of the screen showing when its in a regen mode) as I have been told by those who I trust an those work on theses engines that the ECU only time it add extra fuel is for soot load and 24 hour regens, thus any time the soot load goes down without the auto regen message showing its doing a passive regen, that means the DPF temp has reached a hi enough temp to burn/reduce the soot load in the DPF... I'll attach one of the photos showing the message I see for auto regen. BTW I time my regens so I know if its a 24 hr or soot load regen...

 

[Gr8bawana]

dordoc2506 Well we're still waiting for you to tell where you get these genuine Mopar filters for half price. ​

 

[Goose55]

dordoc2506 Well we're still waiting for you to tell where you get these genuine Mopar filters for half price. ​

Who said that?