How real are DPF issues on a diesel motor?

DingyHarry

Active Member
Joined
Sep 24, 2019
Messages
29
Reaction score
8
Location
NC
Vehicle(s)
2020 JLUR
Just ordered a Wrangler EcoDiesel. I did so for the increased torque to turn larger tires and for the improved fuel efficiency. at 6% below invoice, the difference in cost between the EcoDiesel and the V6 petrol motor was about $2,800. Here is the calculation:

Diesel PLUS transmission invoice price: $5,310 (engine costs $3,560 and transmission costs $1,780)
V6 Petrol PLUS transmission invoice price: $2,300 (engine costs nothing but transmission is $2,300 invoice)

Diesel PLUS transmission at 6% below invoice price: $4,991
V6 Petrol PLUS transmission 6% below invoice price: $2,162

Real world difference in price between Diesel and V6 petrol: $2,829

At 30MPG highway and 450 ftlb of torque for the Diesel, I consider this to be a fairly good deal for the "upgrade" IF IF IF the EcoDiesel is reliable. Obviously we cannot know if this specific engine is reliable as it is a new design. However, is a DPF (Diesel Particulate Filter) system inherently unreliable? I've read the horror stories. But I've also read horror stories about all cars and all types of technologies. Out of millions of consumers, some are bound to have issues. Is the DPF system in diesel motors a fatal flaw to all diesels these days? Or are the issues with reliability largely overblown?





Advertisement

 

jdubya421

Well-Known Member
First Name
Jakob
Joined
Jul 24, 2019
Messages
516
Reaction score
608
Location
Greensboro, NC
Vehicle(s)
2020 Rubicon 2-Door MT V6
Build Thread
Link
In my experience with Diesels the DPF needs to be cleaned and that is basically it. With offroad use you may need to clean it more. The DPF will cause some MPG fluctuations during "cleaning cycles" or whatever it is, but DEF for the most part it is just annoying to refill. My buddy has a 2017 Duramax and all the systems for cleaning the emissions are annoying, but after 70k miles, nothing has broken or need replacing.
 
Last edited:

D60

Well-Known Member
Joined
Apr 1, 2019
Messages
1,519
Reaction score
1,648
Location
CO
Vehicle(s)
JL
If you ever look into a DPF it's difficult to imagine how it doesn't affect power and mileage.

Reliability with a DPF and DEF, I don't know.

But I will say someone will come out with DPF delete on the DL and I'd quietly look into that when it comes, if I owned a diesel.

I've read of guys with the Dmax running EFI Live and just gutted their DPF - the former means no codes to fail emissions and the latter means visual inspection A-OK! And their numbers at the tailpipe are still plenty clean to pass.

But of all my concerns with a 3.0 diesel JL, DPF issues (esp while under warranty) would be WAY, WAY down the list. I think you're worrying about the wrong things.
 

JLURD

Well-Known Member
Joined
Nov 30, 2017
Messages
1,534
Reaction score
2,012
Location
Alaska
Vehicle(s)
2018 Compass Latitude 6MT, 2020 JLUR 3.0
DPFs are not designed for the long haul. Of the half dozen folks I know who currently run modern diesels, they have all had DPF issues across 4 different brands. Both of my VW diesels had DPF failures inside the warranty period. If you think about burning soot into ash with excess fuel at 600-1200 degrees F for several minutes per regen cycle, it’s no surprise why these things don’t hold up for hundreds of thousands of miles. Like any other filter, they will eventually need an overhaul or complete replacement...neither of which is cheap. And that says nothing of EGRs, which have notoriously problematic solenoids and otherwise dump exhaust gases into your intake which is an inherently stupid idea if engine longevity is your goal. DPFs also sap power and efficiency, forcing you to burn more fossil fuels to achieve soot/particulate reductions...a trade-off no environmentalist would like to discuss. They also won’t admit that my 55mpg cheating VWs were producing about the same amount of CO2 as an electric vehicle running off the average US power sources.
 

Shaved Ice

Well-Known Member
First Name
Greg
Joined
Sep 23, 2018
Messages
276
Reaction score
715
Location
Knoxville, Tennessee
Vehicle(s)
2019 JLUR
I had a Cummins with DEF. It crystallized in the tank. The tank and lines had to be replaced (under warranty, but still). The only way I would ever consider another modern diesel would be if I towed regularly. Otherwise the additional cost and maintenance just isn’t worth it.
 
Last edited:

Dkretden

Well-Known Member
First Name
David
Joined
Jan 29, 2019
Messages
2,295
Reaction score
2,917
Location
Denver, CO
Vehicle(s)
2020 JLUR 3.6L
Not a direct analogy but these systems are not loved by commercial diesel heavy truck fleet owners either —- due to weight and maintenance
 

Gorilla57

Well-Known Member
Joined
Jan 3, 2019
Messages
378
Reaction score
438
Location
Chandler AZ
Vehicle(s)
2019 JLUR Mojito
In my experience with Diesels the DPF needs to be cleaned and that is basically it. With offroad use you may need to clean it more. The DEF will cause some MPG fluctuations during "cleaning cycles" or whatever it is, but for the most part it is just annoying to refill. My buddy has a 2017 Duramax and all the systems for cleaning the emissions are annoying, but after 70k miles, nothing has broken or need replacing.
You need to do some research before you spread wrong information out there. There is NO “cleaning cycles” with DEF use. DEF is injected all the time into the SCR, which has nothing to do with “cleaning cycles”. DEF use also doesn’t cause any MPG fluctuations. DEF use is pretty constant @ 3% of fuel use.

The DPF does go through “cleaning cycles” and this does cause MPG fluctuations because the motor is injection more fuel to cause the DPF to heat up to burn off the soot.

Also, since these Wranglers probably won’t be towing, they will get up to 1000mpg of DEF, meaning you’ll refill the DEF tank about every 5k miles. It’s not difficult to stop by WalMart or where ever to get a 2.5gal jug of DEF and top off the tank.
 

jdubya421

Well-Known Member
First Name
Jakob
Joined
Jul 24, 2019
Messages
516
Reaction score
608
Location
Greensboro, NC
Vehicle(s)
2020 Rubicon 2-Door MT V6
Build Thread
Link
You need to do some research before you spread wrong information out there. There is NO “cleaning cycles” with DEF use. DEF is injected all the time into the SCR, which has nothing to do with “cleaning cycles”. DEF use also doesn’t cause any MPG fluctuations. DEF use is pretty constant @ 3% of fuel use.

The DPF does go through “cleaning cycles” and this does cause MPG fluctuations because the motor is injection more fuel to cause the DPF to heat up to burn off the soot.

Also, since these Wranglers probably won’t be towing, they will get up to 1000mpg of DEF, meaning you’ll refill the DEF tank about every 5k miles. It’s not difficult to stop by WalMart or where ever to get a 2.5gal jug of DEF and top off the tank.
You realize those two acronyms are one letter apart right? I fixed my comment and it isn't wrong.

Your DPF goes through cleaning cycles (or regen cycles or whatever it is called, that is why I put it in quotes) and it does that by getting hot, you can clean it out by driving on the freeway. If a Jeep is mostly taken off road with a diesel, you might wanna just ride on the freeway for 20 minutes or so.

Also, I said DEF was fine, just sometimes it is annoying to fill. I didn't say it was difficult. It also depends on where they put the fill port: next to the gas is nice, in the engine bay is, again, annoying.
 

Crux

Well-Known Member
First Name
Matt
Joined
Jul 6, 2019
Messages
64
Reaction score
55
Location
CO
Vehicle(s)
2020 3.0D JLUR ordered
30mpg bahaha

I too am likely getting a 3.0D but expecting 442 ft lb torque and no tunes since they’re now illegal to make and sell.
 

JP18

Well-Known Member
First Name
J.P.
Joined
Jul 10, 2018
Messages
129
Reaction score
83
Location
Columbia, SC
Vehicle(s)
2018 JL Unlimited Rubicon
Those expecting 30MPG out of a JL Ecodiesel are not in tune with reality. My Grand Cherokee Ecodiesel gets about 26-28mpg at best, so a boxier Jeep won't get better, that's for certain.

As for DEF, I fill it once about every 10,000 miles (the Wrangler's DEF tank may be smaller? not sure). However, go to a truck stop and fill it up with the bulk dispenser. (link) There's no need to get it from the store.

JP18
 

Almost

Well-Known Member
Joined
Sep 27, 2019
Messages
77
Reaction score
101
Location
NJ
Vehicle(s)
09 JKU
Those expecting 30MPG out of a JL Ecodiesel are not in tune with reality. My Grand Cherokee Ecodiesel gets about 26-28mpg at best, so a boxier Jeep won't get better, that's for certain.
I think it will be about the same just because the gen 3 motor gets even better MPGs. The truck went from 27 to 30mpg with the gen 3 motor. We had a eco diesel GC in the family as well and consistently got 28mpg on the highway. 22-24mpg with aggressive driving around town.
 

CarbonSteel

Well-Known Member
Joined
Jul 21, 2019
Messages
1,389
Reaction score
1,426
Location
Texas
Vehicle(s)
2019 Jeep Rubicon Unlimited
Vehicle Showcase
1
I can speak from experience with a Ford Powerstroke (2015 6.7L). Below about 15°F, DEF will crystallize and harden and thus many DEF tanks have heaters in them to defrost the DEF. When it melts, it returns to its normal state, but the heaters can be problematic and fail. Since they are typically integrated into the tank, the whole assembly has to be replaced. The SCR system (which uses DEF to become a catalytic converter of sorts) has quite a few sensors on it that can go bad from time to time.

For the DPF, most (if not all diesels) require a regeneration cycle that usually dumps extra diesel into the exhaust either via more diesel through the engine or an extra diesel injector in the exhaust system. For the time the regen is happening MPG will be in the toilet--my 2015 averaged 12MPG during a regen which took about 25-30 minutes at 65MPH. The DPF unit will have to be replaced at some point and if 50/50 stop and go versus all highway, it may need to be replaced between 100-120K miles.

Most modern diesel emissions systems have "nannies" built into them which can cause the vehicle to be limited to a very low speed (25 or so) or be completely non-functional until the problem is resolved (read this stranded on the side of the road). Note that NONE of what I have mentioned above is cheap to replace.

For most people, a modern diesel makes zero sense if its primary function will be stop and go driving. The engine will be in a constant state of regen and your MPG will be atrocious, not to mention at some point you will see the "drive to clean" message appear and if not heeded a trip to the dealer would be in order to correct the problem. There is also increased maintenance and higher fuel costs to consider that when objectively reviewed against a gasoline counterpart rarely add up.

One thing is certain, I would not buy any Jeep diesel without buying the longest time/unlimited mileage warranty that I could find. If leasing and if one does not intend to keep it past the lease, then that is another matter.

As with anything else, YMMV!
 
Last edited:

Gorilla57

Well-Known Member
Joined
Jan 3, 2019
Messages
378
Reaction score
438
Location
Chandler AZ
Vehicle(s)
2019 JLUR Mojito
You realize those two acronyms are one letter apart right? I fixed my comment and it isn't wrong.
Well, then you need to proofread better before you post. Bad info like that about diesels will spread like wildfire. Your comment WAS wrong until you fixed it.
 

wibornz

Well-Known Member
First Name
Ted
Joined
Aug 3, 2018
Messages
3,032
Reaction score
9,004
Location
lansing, Mi.
Vehicle(s)
JL Unlimited Rubicon
Occupation
Retired from Corrections....I have stories.
I thought of waiting on the diesel engine, but did not. The added cost was not worth it. Sure it gets better milage, but the fuel cost about a dollar more per gallon around me. So there is no real savings. Then add in the extra cost of the exhaust fluid. lol and well you will just never be above water on the purchase. Sure the torque will be great, but the the JL has sufficient torque to spin all four wheels slowly or fast when in low anyways so it is kind of overkill.

Mind you I am not mad at anyone for buying a diesel, I have had many of them over the years, but I just don't see the up side in a JL.

Now for a side note that pisses me off about diesel trucks, 2012 F250 stock was getting 12 mpg. Put a tuner on it, bigger exhaust, open up the air box, get rid of the DEF, ERG delete and get 200 more hp and double the mileage. The fucking truck should have came that way.

For the life of me I don't understand how getting 12 mpg is better for the environment than getting 24 mpg.
 
Last edited:

JLURD

Well-Known Member
Joined
Nov 30, 2017
Messages
1,534
Reaction score
2,012
Location
Alaska
Vehicle(s)
2018 Compass Latitude 6MT, 2020 JLUR 3.0
For the life of me I don't understand how getting 12 mpg is better for the environment than getting 24 mpg.
We are told to believe it is because the EPA and CARB said so. There are plenty of folks who don’t believe the trade of efficiency for NOx/particulate (mostly particulate) reductions is rational. Mind you this only reflects the consent of the governed if you believe in 4th branch overreach and chevron deference...in which case you’d be a statist and patently wrong. Welcome to our broken system of government.
 

Advertisement




Smart Stop Start
 



Advertisement
Top