3.0 Duramax opinions/experience??

180ls1

WKR
Joined
Apr 19, 2020
Messages
1,364
Turbo 4 oil leaks. Pcv separator back of head and left side. Turbos.Some low mileage failures. I would stick with 5.3 Some lifter failures. I have a 2024 hd with 6.6 ?

Thanks, and the 5.3 but turn off v4 mode?

My family needs a new SUV and I am a little terrified of the 10 speeds and engine combos costing a lot in an already costly SUV.

My current suv has been unbelievably reliable its just too old.
 

StuckInTheEast

Lil-Rokslider
Joined
Oct 3, 2022
Messages
154
2020 ok later models have seen problems. Fellow employee put 2. 6.2l in same truck. One at 25k second at 28k 2023 model.gm bought it back
6.6 gas having big issues too per my contacts and acquaintances at GM dealers... Just priced one for a guy with a 2020 2500hd with 130k...meticulous maint record, cam/lifter failure with piston to valve contact...You can buy a brand spanking new long block from GM for under $2500...the catch is there is a $7k core charge. Im told this is typical practice when GM is eating alot of them under warranty and wants to reduce costs and needs cores to rebuild.
I hear alot of horror stories of gm vehicles under warranty stacked up waiting on back ordered parts from techs and parts dept guys I talk to first hand. When the people that work there openly and honestly tell you they don't know how GM is still in business...that speaks volumes to me. I hear the same from guys a Hyundai/Kia.

As much as I dislike stellantis for numerous reasons, the Ram 1500s have been pretty solid. Transmissions holding up better than either ford or GM. 5.7 and 3.6l have been good overall...other than 3.6l eating cam shafts now and then. Few lifter/cam failures on 5.7l but not as prevalent as GM.
I've seen way to many people get bit with major engine and/or transmission failures on GM trucks and SUVs with AFM ls and LT series engines and 6,8,10L trans right around 100k miles to ever be confident owning one out of warranty.
Lately it seems GM and stellantis are in a competition to see who can run out of parts to support their products the fastest.

The auto industry as a whole is in bad shape from a value/reliability standpoint across the board. It's pretty disheartening honestly. Cost of ownership has gone up exponentially while quality and longevity have decreased.

As for 3.0L duramax, I've not seen alot of them yet. They run strong. Mileage is good, but not that great considering diesel costs more most places. The only two I have long term(over100k miles) first hand experience with have had major engine or transmission repairs under and out of warranty. Both have since been unloaded. I forsee parts supply issues given GMs track record and the relatively small % of vehicles produced with that engine vs other options. Long-term They will likely expensive to keep going and harder to find parts for than gas counter parts...I would consider other options, not that there are really any great ones out there presently IMHO.
 
Joined
Jun 7, 2018
Messages
727
Location
Tennessee
I've got a 24 with 18k on it. Came from an 04 Chevy with the 5.3. My 24 has been trouble free for me. I love the truck. Drives smooth, gets great milage, and it has towed everything I've put behind it like it's not there but the heaviest was only my ski boat which is only around 5k lbs. I've got the max tow on mine so would like to see what it would do with a 10k plus load but so far it has fit my needs perfect

Sent from my SM-S936U using Tapatalk
 

jstraf

FNG
Joined
Dec 6, 2021
Messages
17
I had a Sierra with the 3.0 for a year back in 21. Put 43k on it, and liked it. Good fuel economy and smooth power. It had a few issues no starting, where it would just crank for 30 seconds and not start, then start normal the next push of the button. Annoying, and a little embarrassing sitting at a gas station around people lol. Otherwise it was a good truck.
 

tdhanses

WKR
Joined
Sep 26, 2018
Messages
6,036
Yeah, I've been reading somethings online saying GM changed the valve from the power train warranty to the 3yr/36K emissions warranty. Hoping that's not the case. I guess I'll find out on Monday.

Also safety recall doesn't fix anything, it hopefully puts the truck into limp mode before failure. Tranny still needs to be replaced, now I just get to drive it slowly to the dealer instead of having it towed.
Safety recall locks out 8-10 gears preventing the lockup, not sure how extensive the repair will be but I’d assume it’ll be covered under warranty and then after might be converted under the recall.

Not that worried about it.
 

Weldor

WKR
Joined
Apr 20, 2022
Messages
2,175
Location
z
Ford and Stellanis dumped their small diesel, only option is GM. Too bad there is no competition, sometimes that makes them step up and improve things or known problems. The only problem I have with new trucks is they all look the same, need to use your fob to find it in the parking lot LOL.
 

tdhanses

WKR
Joined
Sep 26, 2018
Messages
6,036
I’m having a similar problem with mine. 22 Chevy 1500. Check engine light for emissions issues and been to the dealer a few times. Left me stranded this week Monday and needed to be towed back to the shop. I don’t drive it much, it’s more of my plush personal weekend truck and I just always drive my work truck but im losing confidence. If I decide to stick with 2 vehicles I’ll probably trade it for a GMC with the 6.2 gas and say goodbye to 30mpg and hello to no lit up dash.
Before you go to the 6.2 research the big failures it’s had.

My wife has the 6.2 in her Yukon, eats about 2qts of oil in between oil changes and only has 50k on it, have been told it’s within GM spec.
 

keller

WKR
Joined
Oct 30, 2017
Messages
696
Location
wi
Chevrolet from bottom 1.5 to 6.6 top. All burn oil they are the worst oil burning run out of oil vehicles out their. I drive 2003 dodge caravan. I can run 5000 between oil change. Down 1 qt.If it was a equinox it would be out of
Oil.
 

Ucsdryder

WKR
Joined
Jan 24, 2015
Messages
7,000
Was hunting with a guy today that had a 3.0 for a company truck. He said all of them started having issues with def components right before 60k. It was like clock work. In and out of the shop since. I want to say they have 15 or so. They were 2021s
 

tdhanses

WKR
Joined
Sep 26, 2018
Messages
6,036
Was hunting with a guy today that had a 3.0 for a company truck. He said all of them started having issues with def components right before 60k. It was like clock work. In and out of the shop since. I want to say they have 15 or so. They were 2021s
Hopefully my 21 stays rock solid, at almost 71k, no def issues to date.

Mine has been in the shop twice in 4 years, once around 2500 miles for an egr replacement, truck was in and out in a day and the second time for the recall 2 weeks ago, dealer came and grabbed it at 11am and returned it around 3pm to my house.

Was talking with my wife tonight though, might trade her 22 Yukon off for a 25 Yukon and my 21 1500 for a 25 3500, I’ll get a diesel and she’ll probably get another 6.2 but maybe a 5.3 if she doesn’t get another Denali this go around.
 

randy66

FNG
Joined
Feb 23, 2024
Messages
39
Hopefully my 21 stays rock solid, at almost 71k, no def issues to date.

Mine has been in the shop twice in 4 years, once around 2500 miles for an egr replacement, truck was in and out in a day and the second time for the recall 2 weeks ago, dealer came and grabbed it at 11am and returned it around 3pm to my house.

Was talking with my wife tonight though, might trade her 22 Yukon off for a 25 Yukon and my 21 1500 for a 25 3500, I’ll get a diesel and she’ll probably get another 6.2 but maybe a 5.3 if she doesn’t get another Denali this go around.
Same with my 20 at 125k, no def issues and no cold issues. It sits out in Wisconsin winters and hasn't been plugged in once.
 
Joined
Jul 18, 2019
Messages
2,246
6.6 gas having big issues too per my contacts and acquaintances at GM dealers... Just priced one for a guy with a 2020 2500hd with 130k...meticulous maint record, cam/lifter failure with piston to valve contact...You can buy a brand spanking new long block from GM for under $2500...the catch is there is a $7k core charge. Im told this is typical practice when GM is eating alot of them under warranty and wants to reduce costs and needs cores to rebuild.
I hear alot of horror stories of gm vehicles under warranty stacked up waiting on back ordered parts from techs and parts dept guys I talk to first hand. When the people that work there openly and honestly tell you they don't know how GM is still in business...that speaks volumes to me. I hear the same from guys a Hyundai/Kia.

As much as I dislike stellantis for numerous reasons, the Ram 1500s have been pretty solid. Transmissions holding up better than either ford or GM. 5.7 and 3.6l have been good overall...other than 3.6l eating cam shafts now and then. Few lifter/cam failures on 5.7l but not as prevalent as GM.
I've seen way to many people get bit with major engine and/or transmission failures on GM trucks and SUVs with AFM ls and LT series engines and 6,8,10L trans right around 100k miles to ever be confident owning one out of warranty.
Lately it seems GM and stellantis are in a competition to see who can run out of parts to support their products the fastest.

The auto industry as a whole is in bad shape from a value/reliability standpoint across the board. It's pretty disheartening honestly. Cost of ownership has gone up exponentially while quality and longevity have decreased.

As for 3.0L duramax, I've not seen alot of them yet. They run strong. Mileage is good, but not that great considering diesel costs more most places. The only two I have long term(over100k miles) first hand experience with have had major engine or transmission repairs under and out of warranty. Both have since been unloaded. I forsee parts supply issues given GMs track record and the relatively small % of vehicles produced with that engine vs other options. Long-term They will likely expensive to keep going and harder to find parts for than gas counter parts...I would consider other options, not that there are really any great ones out there presently IMHO.

Man I’m about to trade in my 2019 GMC 6.6 Duramax… was leaning really hard to a 3.0L since a majority of my towing is under 10,000 lbs. Have a good friend that’s a diesel mechanic, said he doesn’t care for any of the new diesels.

Now leaning towards grabbing a 6.6L gas 2500, especially since it qualifies for the 179 tax break for business. I think that engine came out in 2020. Hadn't heard of any major issues - @StuckInTheEast can you tell me more?

@keller, sounds like the 6.6 burns a lot of oil - you see any other major issues? You all are going to force me to look at a Ford 3/4T now!
 

StuckInTheEast

Lil-Rokslider
Joined
Oct 3, 2022
Messages
154
Man I’m about to trade in my 2019 GMC 6.6 Duramax… was leaning really hard to a 3.0L since a majority of my towing is under 10,000 lbs. Have a good friend that’s a diesel mechanic, said he doesn’t care for any of the new diesels.

Now leaning towards grabbing a 6.6L gas 2500, especially since it qualifies for the 179 tax break for business. I think that engine came out in 2020. Hadn't heard of any major issues - @StuckInTheEast can you tell me more?

@keller, sounds like the 6.6 burns a lot of oil - you see any other major issues? You all are going to force me to look at a Ford 3/4T now!
6.6l gas is basically a 6.2l with larger bore and longer stroke...otherwise the same and having same issues from what I've been able to gather short of the more prolific crank failures the 6.2 has had. That being said it seems most of those have been at lower miles and under warranty and I've not personally seen one yet just been told about it by dealer connections.
Id hope they corrected the cause on on replacement engines.
Only seen a few 6.6l out of warranty thus far. Last one was classic GM lifter failure at 130k so thats still a thing on the 6.6l
That one had alot a fuel in the crankcase, but no codes stored yet related to that. All the GM direct injection v8 engines have issues with fuel leaking past shaft seal of the high pressure fuel pump into crank case. It will set codes once bad enough but until then it's just putting gasoline in your oil...you can be the judge of whether or not that sounds healthy for an engine that's already prone to lifters seizing in the bore and lifter rollers failing and wiping out camshafts🤷‍♂️

I dont like to hate on any one manufacturer. They all put out 💩 products of one kind or another...but GM has been really bad in my personal experience the last 15+years and not gotten any better. Just seen too many major failures and stupid problems across the board at under 100k miles. Some folks have better luck than others, but I wouldnt own anything GM truck/suv wise newer than 2006 short of and l5p with the 6spd Allison.
The L5P has been solid in the 3/4 and 1 ton trucks but the jury is out on the "Allison" 10spd...(nothing Allison about that trans short of them taking a fat check from GM to stamp their name on it) The 3/4 and 1ton diesel trucks seem to be their last saving grace, but parts supply issues and emmissions control system failures are still common there.
I dont know what to tell people to buy for a truck anymore. Long term quality has taken such a dump across the board. It just seems GM has had alot more major powertrain issues at lower mileage than the other options...other than Toyota...they can take that new twin turbo v6 of theirs and stick it where the sun don't shine... still breaks my heart to see how bad they ruined the tundra
 
Joined
Jul 18, 2019
Messages
2,246
6.6l gas is basically a 6.2l with larger bore and longer stroke...otherwise the same and having same issues from what I've been able to gather short of the more prolific crank failures the 6.2 has had. That being said it seems most of those have been at lower miles and under warranty and I've not personally seen one yet just been told about it by dealer connections.
Id hope they corrected the cause on on replacement engines.
Only seen a few 6.6l out of warranty thus far. Last one was classic GM lifter failure at 130k so thats still a thing on the 6.6l
That one had alot a fuel in the crankcase, but no codes stored yet related to that. All the GM direct injection v8 engines have issues with fuel leaking past shaft seal of the high pressure fuel pump into crank case. It will set codes once bad enough but until then it's just putting gasoline in your oil...you can be the judge of whether or not that sounds healthy for an engine that's already prone to lifters seizing in the bore and lifter rollers failing and wiping out camshafts🤷‍♂️

I dont like to hate on any one manufacturer. They all put out 💩 products of one kind or another...but GM has been really bad in my personal experience the last 15+years and not gotten any better. Just seen too many major failures and stupid problems across the board at under 100k miles. Some folks have better luck than others, but I wouldnt own anything GM truck/suv wise newer than 2006 short of and l5p with the 6spd Allison.
The L5P has been solid in the 3/4 and 1 ton trucks but the jury is out on the "Allison" 10spd...(nothing Allison about that trans short of them taking a fat check from GM to stamp their name on it) The 3/4 and 1ton diesel trucks seem to be their last saving grace, but parts supply issues and emmissions control system failures are still common there.
I dont know what to tell people to buy for a truck anymore. Long term quality has taken such a dump across the board. It just seems GM has had alot more major powertrain issues at lower mileage than the other options...other than Toyota...they can take that new twin turbo v6 of theirs and stick it where the sun don't shine... still breaks my heart to see how bad they ruined the tundra
Danmitall... lifelong Chevy guy here but I've been pretty underwhelmed with my 6.6 Duramax (2019, 140k miles - think that's the L5P). Even left me stranded once with three kids, a puppy, and wife - fuel injector went out on a road trip, 90k miles. That was fun. I had a few in the late 90s and early 2000s that were bulletproof. Whish I still had em. Never thought I'd admit this but I'm contacting a few Ford dealers about the 3/4T 6.8L gasser.

I've convinced myself away from the 3.0L Babymax, though some of the positive reviews sound good. Just don't want to go down the diesel hole again, they've sure lost their luster with EPA meddling. Plus the fuel doesn't pencil out and the 1500s don't qualify for 179 tax break for businesses.

Thanks for the info.
 

keller

WKR
Joined
Oct 30, 2017
Messages
696
Location
wi
I've seen 1 6.6L gas with oil consumption issue. None with engine failure. I'm on my 2nd one had a 2023 now a 2024 traded to get Allison trans that is not actually made by Allison but by gm and branded an Allison. But that's a whole other story. Lol. I havnt put enough miles on to see if either burn oil. We are not a huge dealer. I'm sure others have a better handle on failure percentage.
 

rjschi21

FNG
Joined
Jan 11, 2025
Messages
2
My cousin has one. Loves it 26ish mpg on highway trips. Pulls his 21' bass boat no problem at 17-18 mpg regularly in the summer.
 
Joined
Nov 29, 2023
Messages
83
Mines back in the shop today. If they can work out the problem for good this time Im tempted to keep it. I love the truck and I want to love the motor too.
 
Joined
Jan 2, 2020
Messages
30
I’ve got one of the 2024 LZ0 baby max’s and so far I love driving it. The torque delivery and smoothness is impressive. However, I did have a short in the wiring harness due to a hose clamp rubbing through three wires. That was a pain and cost me a week of not having my truck, but hopefully that’s the only issue for the next while.
 
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