2022 Cummins Regen Issues

[johnsaye]

I have a 2021 Ram 6.7 , same problem. Regens started being an issue at 36,000 miles. To many regens will degrade the oil leading to major engine problems down the road . Went to the Ram dealer in Santa Fe today and was told it’s a problem with most Cummins equipped Rams! I was told they were backed up with these problems and it would be at least July before they could get to my truck! What am I supposed to do ? Try another dealer or park the truck for 2 months? This is a problem the factory is aware of with so far no answers.

 

[nlambert182]

It's more than just Cummins.... you fail to remember that the same equipment is on EVERY modern diesel engine and all of them suffer from similar problems. It doesn't matter what you own, you're going to run into this eventually.

You can thank the EPA. There's only one way to solve the problems and it's not a way that they like.

Powerstrokes:




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Heavy Equipment:

 

[2003F350]

I have a 2021 Ram 6.7 , same problem. Regens started being an issue at 36,000 miles. To many regens will degrade the oil leading to major engine problems down the road . Went to the Ram dealer in Santa Fe today and was told it’s a problem with most Cummins equipped Rams! I was told they were backed up with these problems and it would be at least July before they could get to my truck! What am I supposed to do ? Try another dealer or park the truck for 2 months? This is a problem the factory is aware of with so far no answers.

How is a regen (where it's literally raising exhaust temps after the turbo) going to degrade the oil that you're supposed to be regularly changing out? Beyond that, the engine/oil temp doesn't go up during a regen, JUST exhaust temps. Then I believe (I could be wrong on this, I know more about older DPF systems) that it injects diesel fuel into the DPF to burn off the accumulated soot.

Yes, Cummins says you can go 15k on an oil change. I go 7500, some guys are going 10k, others 5k. Regardless, if you're changing it regularly and keeping an eye on it, it's never going to degrade to a point where you'll have issues anyway.

Edit: reading the above post, looks like a LOT of the issues are from people not paying attention to how their trucks are operating and using cheap/bad fuels. Imagine that - if you don't take care of your vehicle and treat it well, it starts having issues!

As for what to do? Yes, I'd try another dealership, you may also want to look into a completely different diesel mechanic.

 

[Choupique]

Cummins doesn't use exhaust injectors. The exhaust temperature is raised in cylinder. The added fuel and added heat is definitely hard on oil. Riding around in perpetual regen is very hard on everything.

 

[nlambert182]

Cummins doesn't use exhaust injectors. The exhaust temperature is raised in cylinder. The added fuel and added heat is definitely hard on oil. Riding around in perpetual regen is very hard on everything.

Well, they do.. but it is a DEF injector versus a diesel injector. DEF is injected after the DPF based upon the amount of soot that the sensor sees. That injection creates a reaction with the nitrogen oxides in the exhaust and turns it into nitrogen and water. You'll sometimes see a stain trail on the bottom of the inside of the exhaust pipe. This is why.

Once the DPF reaches an internal temp of close to 600 degrees F, a passive regen will occur naturally. When a full on regen is required, fuel is injected on the exhaust stroke and pushed into the Nox canister where it is ignited. That increases the temps to 1100-1200 degree F. Once the cycle reaches 40%, active regen shuts down and passive regeneration takes back over until you're back to zero.

The heat isn't raised in cylinder (cylinder temps remain roughly the same) since the fuel is ignited in the exhaust between the engine and the DPF. It does not impact your oil.

 

[nlambert182]

How is a regen (where it's literally raising exhaust temps after the turbo) going to degrade the oil that you're supposed to be regularly changing out? Beyond that, the engine/oil temp doesn't go up during a regen, JUST exhaust temps. Then I believe (I could be wrong on this, I know more about older DPF systems) that it injects diesel fuel into the DPF to burn off the accumulated soot.

Yes, Cummins says you can go 15k on an oil change. I go 7500, some guys are going 10k, others 5k. Regardless, if you're changing it regularly and keeping an eye on it, it's never going to degrade to a point where you'll have issues anyway.

Edit: reading the above post, looks like a LOT of the issues are from people not paying attention to how their trucks are operating and using cheap/bad fuels. Imagine that - if you don't take care of your vehicle and treat it well, it starts having issues!

As for what to do? Yes, I'd try another dealership, you may also want to look into a completely different diesel mechanic.

It doesn't.

I agree that some issues are caused from user error, but more often than not it's the system itself. It's overly complicated and things like the DPF are considered replaceable. They're not intended to last the life of the vehicle. Quality of fuel, additives, how the truck is used, etc... have an impact on how long it lasts. There are just too many variables for the computer to adjust enough to extend the life. It has baselines that it follows. If you fall outside of those baselines (like a daily commuter that uses poor quality diesel and dumps in a bunch of unnecessary additives while stretching fuel filter changes) then you're likely to see a failure sooner.

 

[Choupique]

Well since you opened the can, there's a few corrections needed. Don't take it the wrong way, trying to make sure the information out there is accurate. Some of your understanding of how this works is crossed up.

DEF is injected at a rate determined largely by the NOx tables in the engine calibration. It is reading its environment measurables, comparing those to a software table that says how much def to squirt in those conditions, verifying it against the NOx sensor readings. The only smoke sensor you have is DPF inlet pressure and is mostly independent of NOx control. PM control and NOx control are totally separate, and you can have one without the other in some applications.

Exhaust temp raised in cylinder just means there isn't a fuel injector in the pipe. All of the post injection and goofy timing going on is a major driver of fuel dilution in the lube oil and id venture to say becomes the primary issue with frequent regens. Perpetual operation in regen is mechanically hard on everything because the engine is running stupidly, you are having fuel washing the cylinders, and some really high temps everywhere.

DPF life is theoretically only limited by how much non-combustable stuff gets shoved down the pipe or how much catalyst poison goes through it. When you are in active regen too much, the heat cycles can break it.

 

[nlambert182]

I don't disagree with you and I tried to over simplify it but I don't think I crossed anything up. It's essentially what I was trying to say. The only part I disagreed with was the cylinder temp increase. There's no noticeable increase in that because the heat that drives the regen happens in the NOx canister. But yes, frequent regens will eventually kill the DPF. Regens do happen based on the amount of soot that the DPF acquires so if you're running bad fuel, granny driving, etc..... then the regens are going to be more frequent and they are going to shorten the life of the DPF.

To my original point, ALL diesel engines have a similar system so it really isn't up to Cummins to fix a system that no one else has figured out. The industry has a method that works for a while and that's about the best anyone can hope for. The EPA is the cause and is killing engines that once would go 250-500k miles relatively trouble free. So like I mentioned before, the only way to make this a trouble free engine is to get rid of it.