Repercussions of regeneration?

summer4x

Well-Known Member
Joined
Aug 27, 2020
Messages
210
Reaction score
273
Location
Rotating Orb
Vehicle(s)
many
I few people mentioned that it was hard following what I was saying. Let me put it another (albeit extreme) way:

Hypothetical: If one was NEVER able to burn off soot by getting the exhaust hot enough, and ALL soot burn-off was ALWAYS a result of regeneration, other than using more fuel, is the DPF (or anything else) being harmed?

Now back to my situation:
I picked up the Jeep with 21 miles on it and I drove it home at sustained high speeds (up to 80mph) for 40 miles. When I got home, a Scangauge showed 63% level of soot. And...this is the soot level after just 61 miles, with 2/3 of the miles being high-speed highway miles. 80mph + 104 degrees ambient seems like the DPF should be loving life - not building up soot.

The soot is always going to burn off as a result of regeneration, either passive or active. Passive regeneration, which you have experienced, is ideal because the engine is not injecting any additional fuel to assist with regeneration. It is accomplishing it based upon the high heat already present in the exhaust system.

Active regeneration is accomplished by injecting raw fuel into the exhaust during the exhaust stroke of the engine where it will ignite and raise the temperatures downstream to allow the soot to burn off in the DPF. The negative effect of this type of regen has been known to be worse fuel mileage but also fuel dilution in the crankcase, which can wash down bearings and lead to premature engine wear and failure. Therefore, passive regen would be the ideal way to handle the soot.
Advertisement

 

Frezski

Well-Known Member
First Name
Allan
Joined
Dec 17, 2019
Messages
286
Reaction score
968
Location
Central Coast, California
Vehicle(s)
2019 JLUR, 2013 F250, 2016 Accord, 2016 Yami R1M
Occupation
Slave to the Trade
Vehicle Showcase
1
@summer4x, is that how the 3.0L is set up? Just out of curiosity is all.
 

GtX

Well-Known Member
First Name
David
Joined
Nov 9, 2019
Messages
1,056
Reaction score
1,448
Location
Illinois
Vehicle(s)
2020 JLUR 3.0D
Occupation
Working for the man.
Vehicle Showcase
1
If you run the rig hard enough to raise exhaust temps high enough it will passively burn soot out of the DPF. If you don't it'll inject fuel to raise temps and actively burn it out.
 

Badweissenbier

Well-Known Member
First Name
Bad
Joined
Aug 6, 2018
Messages
240
Reaction score
197
Location
WV
Vehicle(s)
2018 Billet JLUR
Also to add for the OP. Soot loading won’t hurt the DPF unless you get past the magic threshold where the ecm won’t allow an active regen.
DPFs are a filter, they catch soot and ash(nonburnable stuff in your oil) because of ash loading replacement/cleaning is required at some point. Proper oil and change interval is very important to dpf lifespan way more than soot load. Engine oil burn is what puts the ash into the dpf so wrong oil = high ash problems.
As others have said Exhaust heat is your friend, as it promotes the catalytic reaction to ‘burn’ off the soot.
 

Frezski

Well-Known Member
First Name
Allan
Joined
Dec 17, 2019
Messages
286
Reaction score
968
Location
Central Coast, California
Vehicle(s)
2019 JLUR, 2013 F250, 2016 Accord, 2016 Yami R1M
Occupation
Slave to the Trade
Vehicle Showcase
1
When you say "set up," can you be more specific?
I was curious, every manufacturer designs are different, and I wasn't sure if this 3.0L was set up to dump fuel in the exhaust stroke of the motor. I know most are set up this way. The powerstroke only dumps fuel in the exhaust stroke on one bank only. The duramax LML series have a 9th injector that dumps fuel directly post turbo's down pipe. Since the DPF and oil dilution is always a topic of concern, I hoped that maybe manufactures would come up with a different solution. No hate here. I'm just staying in tune with the modern diesel world. I don't own a Diesel Wrangler. I considered it, but opted for a gas motor out of simplicity since modern diesels are complicated. If I used it for commuting purposes then, I would have for sure picked one up though.
 

bruno747

Well-Known Member
Joined
Sep 26, 2018
Messages
131
Reaction score
97
Location
Colorado
Vehicle(s)
2017 Rubicon Recon 2dr 6spd
Question: if the Jeep needs to go in regeneration mode to get the soot levels down what are the implications? Is this simply a case where it will use more fuel during the it-reached-80% mode - or - is there a more sinister repercussion down the road? If I'm not concerned about the fuel usage issue during regeneration, is all well otherwise? In other words, is life with regenerations okay?
TL;DR regens are not a bad thing. Follow what your evic says and treat the diesel with common sense that it needs to get up to proper operating temp weekly and you will be fine. Ignore messages only take short trips, and you will be in the shop before long.

I'll try to make this a clear as possible.

If you allow the system to work as designed, in that you either never see the regen needed message (becuase the vehicle is being driven long enough to get up to temp), or when you do see the message, you actually drive it enough to clear it, then no, there shouldn't be any real repercussions.

However, driving it in such a way that makes it tell you it needs to do a regen on the dash more than once every few months is not great. Thats harder on the DPF and everything upstream from a back pressure standpoint. It also tends to stack layers of soot up in the DPF that is harder to burn off (longer high temp driving needed to clear it)

Where you get into real trouble is if you blatantly ignore the regen needed keep driving message. If you start treating this system that way you will eventually hit a state where the engine thinks (more or less) hey my driver is an idiot I cant trust it to follow directions. I'm gonna give it 500 (or whatever it is now) miles to take me to a dealer and have the DPF manually cleaned. When this happens, it will literally pop up on the screen and tell you engine will not restart after xxx miles DPF must be cleaned (or similar not sure of the exact wording anymore)

At this point there are 3 possible solutions, all requiring the dealer or a tool for the computer.

1 The dealer uses their computer, acknowledges that a regen is needed, they manually start one and take it for a drive until the computer is happy (ie what the driver should have done paying attention to the evic message)

2 The dealer has to remove the DPF and either clean it by hand or take it to a shop that does DPF cleaning. They reinstall, and manually tell the computer the DPF has been cleaned. Computer checks back pressure and confirms.

3 The dealer simply refuses to do option 1 or 2 and says it needs to be replaced, or the DPF is damaged from mistreatment and cannot be cleaned and reinstalled because the filter is compromised and has to be replaced. New DPF is installed, computer is told DPF has been cleaned, computer checks back pressure and confirms.
 
Advertisement

ATO4x4
 
Advertisement
Top