2015 Chevy 2500HD Diesel Exhaust Problems

Colossus · July 27, 2016

Just to update my issue-

I did take the truck back last month to have them look into the frequent regen issue. I was first told that because my truck had such high engine hours, which indicates the truck saw a lot of idle time vs actual millage- there may not be much GM can do for me. Indeed, I'm betting it did see a lot of idle time, as the previous owner used it up in the oil fields of Wyoming and Nebraska and South Dakota, which would mean it didn't get full regens done, since the regen system on the GM trucks is designed to take place while the vehicle is traveling above a certain MPH and for a certain length of time. None the less, they did take a look and found that the injector that injects diesel into the DPF for the cleaning process was out of bounds by a few degrees.. so that was covered under warranty. They did 2 service regens on it and said give it a shot now. Sadly though- after about 1000 miles- I'm still going into regen every 120-150 miles. Considering the regen cycle takes about 30 min and 30 miles at highway speeds- it's not a good situation. I'm now almost to 70,000 miles on the rig. I'm hoping I can convince my dealer to try to convince GM to approve a warranty replacement of the DPF, as I live in a county that requires emissions testing every 2 years, so the DEF & DPF delete is not an option for me. I fear that the regen cycle will continue to drop until I eventually have no choice but to have the DPF replaced otherwise I'll be stranded.

As much as I love my dealer for all the efforts they have put in on my behalf in dealing with GM- I could never recommend a new Duramax to anyone given how poorly the emissions system performs and won't hold up to the kind of work it sees in the real world such as the work the previous owner of my truck did. I do have to wonder though why GM can't design a system that will allow regens to take place while the truck is in park. A friend of mine who is a OTR driver for UPS drives a 2012 International twin screw- and it is designed to where they do the regens while the truck is parked. It raises the RPMs and 15 minutes later- the regen is done and they drive away, good to go for several thousand miles before having to do another regen.

KMGZ400 · July 27, 2016

I removed all emission from my LML with under 10k miles on it.. Best thing I ever did.

JRKRACE · August 5, 2016

My truck is basically all city and the regens sometimes get completed in 2 days instead of 1 in some cases. 20K trouble free miles so far. My son's LBZ has an Edge CTS2 monitor and when he updated it, it included options to do a force regen or a parked regen on the DPF equipped Duramaxes. I tried it out on my LML and sure enough, it was there. Kind of nice to be able to do your own regens when needed..

Colossus · August 5, 2016

That has to be nice. MIght have to look into that if I get a new DPF since the one I have now seems to be clogged to the point that regens no longer make a difference. I'm stuck with regens every 90-130 miles.

20L8TSierra24 · August 10, 2016

Subscribed. I just bought a Duramax and I do a lot of city towing and they're short distances. My truck is regening ever 450-500 miles at the moment. The truck does increase the RPMs at idle to about 800 or so if the truck is sitting during this cycle.

Colossus · August 11, 2016

Yup, that is normal and about where you should be, Bowtie. Just get her out on the highway sometimes when she goes into a regen, you'll be grateful you did. I have to wonder what fire departments and Ambulance companies do with so many short driving trips and no real long trips with their DPF equipped trucks..

fannin · August 11, 2016

Yup, that is normal and about where you should be, Bowtie. Just get her out on the highway sometimes when she goes into a regen, you'll be grateful you did. I have to wonder what fire departments and Ambulance companies do with so many short driving trips and no real long trips with their DPF equipped trucks..

I'm assigned to a busy Engine Company in Washington DC. We average around 5500 runs a year. Last January(2015) we received a new Pierce Engine with a Detroit Diesel with DPF and DEF. It has to manually placed into Regen, when it first arrived this was a daily ordeal sometimes twice. After a few months it received a software update and now we're down to twice a week or so. It goes through about 5 gallons a DEF every other day. It currently has around 30k miles, which is quite a bit seeing as how we usually only go 1 to 2 miles round trip each run.

Our ambulance is a little busier, but it regens on its own mainly because it has to cross town to goto the hospital which sometimes involves highway driving. Every once in a while you will have to do a parked regen with it, but not nearly as much as the Engine. It also drinks the DEF.

sdeeter19555 · August 12, 2016

Isn't the emissions equipment warranty 8 years or 80k miles for EVERY manufacturer as mandated by EPA?

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20L8TSierra24 · August 14, 2016

Yup, that is normal and about where you should be, Bowtie. Just get her out on the highway sometimes when she goes into a regen, you'll be grateful you did. I have to wonder what fire departments and Ambulance companies do with so many short driving trips and no real long trips with their DPF equipped trucks..

I have a state road I hit when it's in regen where the speed limit is 60. I just drive back and forth a couple times

Peterd · February 12, 2017

I've been reading with great interest for the past six weeks as my 2015 with 94000 miles lite the engine light then a message keep driving cleaning exhaust filter, etc. First the def tank and heater were replaced, a week later a letter from GM with a form to fill out had I paid for the repair. Upon next regen same issues. After a week they gave it back all cleaned our!!! Next regen same issue. After another week in the shop I got it back with a new cat and down pipe. Next regen no lights but hung on regen. After another three days in the shop got it back with new injectors in the exhaust system. Next regen lasted 27 miles a record for this truck as it had been going 40'to 70 plus miles to complete a regen.

Dealer was great, GM hung in testing everything from fuel to air cleaner, over the six weeks. Hope it is now resolved but won't know for a few days. After a few successful regents my confidence should return.

Can only image the trouble one would have without an exceptional dealership. Glad I had all the service work etc done at the same service center.

Cowpie · February 12, 2017

As many heavy truck owners realize, the DPF filter has only a certain number of regen cycles it can do and then it has to be cleaned out or replaced. When regen cycles become frequent, it is time to clean or replace the filter. Since the GM one is not a canister style that contains a removable DPF filter that can be put on a cleaning machine, the entire unit has to be replaced. Big bucks.

I haven't kept up on it myself, but I was under the impression that the emissions stuff does have the 8 yr / 80,000 mile warranty as mandated by the EPA that is separate from the drivetrain or vehicle warranties. Did a little checking, though not a thoroughly detailed check, and the California Air Resources Board, which the defecto toughest standards on this kind of thing, show only a 5 yr, 60,000 mile warranty requirement for DPF's on a vehicles under 19,000 lb. So if that is the case, then doubtful that there is a longer warranty requirement from the EPA on the DPF's.

Peterd · February 12, 2017

GM exhaust warranty is a moving target. Think it was part of drive train warranty which was good to 100000 miles. Was first told that and then receive word it has been increased to 120,000.

International truck's bottom suffered over the past couple years as the had real problems keeping up with the desiel exhaust warranty work.

Hope both are now corrected

Peterd · February 19, 2017

Hurray!! Went a bit over 500 miles, regen cycle took about 40 miles and idle dropped.

Beginning to think it is now fixed

Anybody having exhaust issues hang tough eventually it will be resolved

20L8TSierra24 · February 22, 2017

Hurray!! Went a bit over 500 miles, regen cycle took about 40 miles and idle dropped.

Beginning to think it is now fixed

Anybody having exhaust issues hang tough eventually it will be resolved

Glad to hear yours is fixed . My regens are about 500 miles apart and last for 30-35 mi total. I do step on it hard about 20 miles into a regen and see a big cloud of ash come out every time.

Downhill Duramax · November 30, 2017

Folks we're being scammed. Not only is it ridiculous that we pay a hefty premium for an HD diesel that has proven to be unreliable. Then GM rubs salt in the wounds by refusing to acknowledge and take care of the the root cause & secondary issues caused by their diesel emission failures. Most importantly, for those of us unlucky enough to experience the "reduced engine power" mode this issue will lead to serious injury or death. My 2015 Duramax has gone to this limp mode 3 times while traveling at highway speeds all because their emission system technology sucks. (Yes, there was DEF fluid all three times).