Exhaust System Regeneration?

Badweissenbier

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There are 2 main types of regen:
passive- this happens naturally whenever the exhaust gets hot enough for the reaction to happen.

Active- this happens whenever passive can’t keep the soot regen’d out of the dpf. The computer sees the soot load get to high so it will then take control, elevate the exhaust temperature(by adding fuel late in the combustion cycle so it passes into the exhaust) and cause the regeneration reaction to happen.

Neither is bad under normal conditions however excessive active regens can cause fuel dilution of your oil.

Heat in the exhaust is your friend, it keeps the soot load down. Long idle periods and short trip are very bad on modern diesels.
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GtX

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There are 2 main types of regen:
passive- this happens naturally whenever the exhaust gets hot enough for the reaction to happen.

Active- this happens whenever passive can’t keep the soot regen’d out of the dpf. The computer sees the soot load get to high so it will then take control, elevate the exhaust temperature(by adding fuel late in the combustion cycle so it passes into the exhaust) and cause the regeneration reaction to happen.

Neither is bad under normal conditions however excessive active regens can cause fuel dilution of your oil.

Heat in the exhaust is your friend, it keeps the soot load down. Long idle periods and short trip are very bad on modern diesels.
Bad how?

Bad in that active regen happen more frequently?
 

Badweissenbier

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Bad how?

Bad in that active regen happen more frequently?
It allows soot buildup and not enough heat for passive regen to happen so yes you’ll get more active regens which uses fuel lowering your mpg and potentially causing fuel dilution.
 

GtX

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It allows soot buildup and not enough heat for passive regen to happen so yes you’ll get more active regens which uses fuel lowering your mpg and potentially causing fuel dilution.
How does fuel dumped into the exhaust dilute oil? And, I didn't buy a diesel for mpg.
 

Badweissenbier

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How does fuel dumped into the exhaust dilute oil? And, I didn't buy a diesel for mpg.
Blow by- small amounts always make it by the rings. Excessive active regens add up. Chevy had a real problem with this early on as all their dosing fuel was added from only the back 2 cylinders causing wash down. In their case it was wiping out the cylinders.
 

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Blow by- small amounts always make it by the rings. Excessive active regens add up. Chevy had a real problem with this early on as all their dosing fuel was added from only the back 2 cylinders causing wash down. In their case it was wiping out the cylinders.
To clarify, this is only an issue on engines that inject the cylinder during the exhaust stroke. Some of these emissions systems have an additional injector on the actual exhaust downpipe that injects diesel after the engine to avoid this.

Has anyone checked or verified if the system on the ecodiesel has the extra injector?
 

Badweissenbier

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To clarify, this is only an issue on engines that inject the cylinder during the exhaust stroke. Some of these emissions systems have an additional injector on the actual exhaust downpipe that injects diesel after the engine to avoid this.

Has anyone checked or verified if the system on the ecodiesel has the extra injector?
That’s a good point, in my field usually the large engines have the extra injector and the small use in cylinder. I have not checked on the Jeep.
 

GtX

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To clarify, this is only an issue on engines that inject the cylinder during the exhaust stroke. Some of these emissions systems have an additional injector on the actual exhaust downpipe that injects diesel after the engine to avoid this.

Has anyone checked or verified if the system on the ecodiesel has the extra injector?
From what I've read the ED is injecting into the cylinder unfortunately.
 

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8600 miles and I have never seen a regen message. Have filled the DEF tank 3 times so I know it is doing regen's
 
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I'm almost at 10k miles now and haven't seen that message pop up again. It might have had something to do with my throttle issues?
 

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Guys (and gals if there are some reading)........this stuff has been said before, but I'll word it a bit differently.

If you see the dash tell you that you are in a regen cycle, then it's potentially a BAD thing. Your driving style as of late hasn't allowed your DPF to fully burn off the soot. Your system will do passive and active regens without you ever knowing, that's how the system is designed. When the DPF filter is too full and you have shut down your Jeep too many times during a regen, then you WILL get the message and you need to keep driving it until it says you are ok to stop.

As for DEF, it is NOT part of the regen cycles. DEF is injected into the SCR, the filter that is after the DPF, hence no part of the regen. DEF usage is based off of diesel usage, so it's usage will go up ever so slightly during a regen, just due to the fact that the system uses diesel fuel to ignite the DPF to burn off the soot.
 

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I put a ScanGauge in my rig specifically to monitor soot levels and regen state. I'll do everything in my power to not shut the rig down during an active regen.
 

Compression-Ignition

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I put a ScanGauge in my rig specifically to monitor soot levels and regen state. I'll do everything in my power to not shut the rig down during an active regen.
GtX this is not really aimed at you, but your reply did prompt mine. This is more an opinion drop for anyone that may find this topic later.

Shutting down during a regen is not the end of the world. We have 3400 miles on our 3.0 JLURD (this jeep is driven in town predominantly). IIRC it has 13 regens under it's belt. I know for a fact at least 2 of those my wife missed that it was in regen and shut it down without completing the regen process. Since we have a scangauge, she can monitor the soot level and try to catch the regens in action and make sure they run their course.

I don't recall what the odometer read when we installed the scangauge, but we could have easily missed several more regeneration cycles and shut down in the middle of them. Shoot in actuality shutting down in the middle probably wouldn't be a big deal ever. Shutting down right after the beginning of one? I think that would be the killer.

I'm just saying, I don't think people should be terrified of shutting down during a regen. I told my wife if she ever discovers her Wrangler is in a regen on the way to work and it hasn't completed the cycle, do not worry about it. Park the Jeep and forget about the regen. Not ideal, but I don't want her worrying about it. I think 2 or 3 times now she has told me that her soot level is at 75+ and I have gone and drove her Jeep around to get it completed.

I wouldn't make a habit of shutting down in regen, but IMO it absolutely isn't the end of the world.

FCA and any other manufacturer that doesn't include a way to monitor regen status is doing the owner/operator a disservice. And this exclusion is why so many people default to the idea that if you don't run a diesel on the highway daily, you're doing it wrong. I disagree. All we need is the ability to monitor the regeneration process and tons of these issues could be mitigated.
 

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The guy above me is correct. Shutting down during a regen is okay if not done often or somewhere that flammable material might be under the vehicle like long dry grass.

You just don't want to do it often that and many short drives are where problems start
 

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GtX this is not really aimed at you, but your reply did prompt mine. This is more an opinion drop for anyone that may find this topic later.

Shutting down during a regen is not the end of the world.
I agree completely CI. I'm pretty sure I shutdown once before the ScanGauge was installed. I pulled into the garage, shutdown, and noticed a peculiar odor. The JL saw 4 regents before the ScanGauge was installed according to it.
 
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