OT: GMC Duramax 3.0

cowbell88

Well-known member
Jan 11, 2009
2,898
529
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I’m looking at a truck that has this engine in it. It is the IZO and not the LS2 and is a 24 model.

Anybody have one and can give me some info?
 

Delmar

Member
Jan 8, 2008
395
120
43
I have a '24 GMC AT4. Only 7500 miles so far, but I love it. Great gas mileage. First time owning a diesel but so far so good.
 

Xenomorph

Well-known member
Feb 15, 2007
13,647
4,628
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I’m currently in a ‘23 Chevy with the 3.0 Duramax. I love leaving the pump and the computer saying 630 miles to empty. I don’t pay for fuel and I do very little towing so I can’t speak to those issues.

All things considered, I love this truck.

Also.. I think the ‘25 horsepower and torque numbers are slightly better than mine.
 

T-TownDawgg

Well-known member
Nov 4, 2015
3,826
2,263
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Do your research. Everybody gonna love that thing, til it breaks.
Last I checked, it has a 17ING OIL PUMP BELT. Typical GM. Ford does same kind of shitt.

I watched a YT video where a GM tech outlined the procedure and cost of replacing this belt, and it was a steep bill for something that has to be done every 100k miles, that is, if the emissions systems don’t fry the engine by then anyway.
 

Anon1717806835

Well-known member
Jun 7, 2024
195
554
93
I’m looking at a truck that has this engine in it. It is the IZO and not the LS2 and is a 24 model.

Anybody have one and can give me some info?
Just got the wife a 2024 Yukon with the 3.0 Duramax. Only had it since September, but no complaints so far. Good mileage and power.
 

BIGDAWG44

Active member
Aug 22, 2012
541
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Supposedly the transmissions are going out at about 100k and there’s been a faulty compression code that gives a fake check engine miss fire code. That’s the only issues I’ve seen
 

cowbell88

Well-known member
Jan 11, 2009
2,898
529
113
Supposedly the transmissions are going out at about 100k and there’s been a faulty compression code that gives a fake check engine miss fire code. That’s the only issues I’ve seen
Thought that was with the LM2 model.
 

Delmar

Member
Jan 8, 2008
395
120
43
Do your research. Everybody gonna love that thing, til it breaks.
Last I checked, it has a 17ING OIL PUMP BELT. Typical GM. Ford does same kind of shitt.

I watched a YT video where a GM tech outlined the procedure and cost of replacing this belt, and it was a steep bill for something that has to be done every 100k miles, that is, if the emissions systems don’t fry the engine by then anyway.
Originally the oil belt change interval was 150k miles, starting in ‘23 the interval is 200k miles.
 

baddmann007

Member
Sep 26, 2023
68
100
33
Wife has a 2021 Escalade with 3.0 Duramax LM2. She loves it (especially the fuel mileage). Only issue we have had is an exhaust rattle at 20k.
 

DesotoCountyDawg

Well-known member
Nov 16, 2005
22,517
10,255
113
No doubt. Vehicles were much more reliable 10 years ago. All the new electronics can be huge reliability issues. For every make & model. Cars & trucks are much worse lately.
A lot of the issues of late with Toyota and Hyundai are poor quality components in the motors. My neighbors Toyota truck is in the list of VINs with a faulty component. They’re going to completely replace his motor.
 
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patdog

Well-known member
May 28, 2007
49,001
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A lot of the issues of late with Toyota and Hyundai are poor quality components in the motors. My neighbors Toyota truck is in the list of VINs with a faulty component. They’re going to completely replace his motor.
Yeah. Lot of stupid cost cutting going on. They changed the valve seals in my car for my model year. Of course they leaked leading to oil leakage. So they had to warranty a lot of valve seal replacements, including mine. My car is fine since they put the old valve seals in. But would have been a hell of a lot cheaper for them to just keep using the old seals.
 

stateguy

Member
Sep 2, 2012
314
16
18
2023 GMC AT4 with the baby duramax. 25k miles.
Biggest issue so far is the oil changes. It calls for DEXOS D. Only 8 oils certified to this standard a few months ago when I found a list.
Given oil requirement - it's pretty much oil changes at dealership only.
Some have trouble with burning oil. I've added oil twice.
 

Delmar

Member
Jan 8, 2008
395
120
43
2023 GMC AT4 with the baby duramax. 25k miles.
Biggest issue so far is the oil changes. It calls for DEXOS D. Only 8 oils certified to this standard a few months ago when I found a list.
Given oil requirement - it's pretty much oil changes at dealership only.
Some have trouble with burning oil. I've added oil twice.
I do my own oil changes, but Mobile 1 has a dexos D oil and I can get it at my local Walmart. You can buy the AC Delco stuff from Amazon fairly reasonable.
 

greenbean.sixpack

Well-known member
Oct 6, 2012
6,345
4,975
113
Honestly I’m not sure there’s any vehicle that’s a sure thing now for reliability.
The last full size truck worth a **** was the Tundra and they effed that up with the 2022 redesign. If I can ever get any of my kids out of college I'm going to buy a 2021 Tundra with less than 100k on it. My current truck is a 2012 Tundra with 230+k miles on it, never an issue.
 

BoDawg.sixpack

Well-known member
Feb 5, 2010
4,424
1,495
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The golden years for GM trucks is 2010-2012. That's going to be the sweet spot for performance, reliability, DIY capability and cost/availability of parts. These trucks will do 85% of what the new ones will do for %30 of the price.
 

DesotoCountyDawg

Well-known member
Nov 16, 2005
22,517
10,255
113
The golden years for GM trucks is 2010-2012. That's going to be the sweet spot for performance, reliability, DIY capability and cost/availability of parts. These trucks will do 85% of what the new ones will do for %30 of the price.
My 2013 Duramax had the faulty fuel pump that disintegrated. Had to have a full fuel system replacement. My 2018 had a bunch of issues with the DEF. I have a 2021 with almost 100,000 miles and knock on wood I’ve had zero issues.
 

PooPopsBaldHead

Well-known member
Dec 15, 2017
8,039
5,359
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I’m looking at a truck that has this engine in it. It is the IZO and not the LS2 and is a 24 model.

Anybody have one and can give me some info?
As a rule, buy a diesel if you need one. They are built for towing and driving long distances, not short empty trips around town. I don't know how much you drive, or how important saving a little here and there is, but I would guess the increased mileage vs the extra expense of maintaining a diesel (def, higher fuel prices, expensive maintenance) will make the savings negligible. If it's mostly around town you may be dealing with frequent regens and it will drive you nuts. Cold days are fun too.

I pull a 9,000 lbs RV in the Rockies and went with a gas burner over diesel in my 3/4 ton. I sacrifice a bit of easy towing up Teton pass but otherwise it was a no brainer. Most of my driving (hours not miles) is running around town. Even when I tow the mileage is only 2-3 mpg lower than it's diesel equivalent which is more than made up for with cheaper fuel. It also gets cold where I am and below 15°-20° you have to worry about fuel gelling.

If I were looking at GMC's and I cared about moderate or greater towing and/or acceleration, I would just go 6.2 gasser and sleep like a baby. I'd bet it's the single best 1/2 ton truck engine on the road today. But if you put 30k of highway miles a year on a truck and don't like the temptation of a big V8 under your heavy foot, the 3.0 may be your answer.
 

Ranchdawg

Well-known member
Dec 13, 2012
3,214
2,362
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2023 GMC AT4 with the baby duramax. 25k miles.
Biggest issue so far is the oil changes. It calls for DEXOS D. Only 8 oils certified to this standard a few months ago when I found a list.
Given oil requirement - it's pretty much oil changes at dealership only.
Some have trouble with burning oil. I've added oil twice.
I thought all GM vehicles were designed to burn oil. My brother-in-law bought a 1500 and it used a quart of oil every 2,000 miles. He said it was normal for that truck. Years ago I had transmission problems with a GM. I haven't had any issues since trading it in and staying away from GM.
 

DesotoCountyDawg

Well-known member
Nov 16, 2005
22,517
10,255
113
As a rule, buy a diesel if you need one. They are built for towing and driving long distances, not short empty trips around town. I don't know how much you drive, or how important saving a little here and there is, but I would guess the increased mileage vs the extra expense of maintaining a diesel (def, higher fuel prices, expensive maintenance) will make the savings negligible. If it's mostly around town you may be dealing with frequent regens and it will drive you nuts. Cold days are fun too.

I pull a 9,000 lbs RV in the Rockies and went with a gas burner over diesel in my 3/4 ton. I sacrifice a bit of easy towing up Teton pass but otherwise it was a no brainer. Most of my driving (hours not miles) is running around town. Even when I tow the mileage is only 2-3 mpg lower than it's diesel equivalent which is more than made up for with cheaper fuel. It also gets cold where I am and below 15°-20° you have to worry about fuel gelling.

If I were looking at GMC's and I cared about moderate or greater towing and/or acceleration, I would just go 6.2 gasser and sleep like a baby. I'd bet it's the single best 1/2 ton truck engine on the road today. But if you put 30k of highway miles a year on a truck and don't like the temptation of a big V8 under your heavy foot, the 3.0 may be your answer.
Agree with this and if you want towing ability just get the Allison Transmission in the gas burner. I’ve had 5 Duramax trucks since 2004 with over 100k on all of them and had zero issues with the Allison.
 
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PooPopsBaldHead

Well-known member
Dec 15, 2017
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Agree with this and if you want towing ability just get the Allison Transmission in the gas burner. I’ve had 5 Duramax trucks since 2004 with over 100k on all of them and had zero issues with the Allison.
A 6.7 Powerstroke engine and Allison transmission is the heavy towing dream team. But I'd say Duramax is much closer to Powerstroke than the Ford transmission is to Allison. If I went diesel, GMC is the choice.

Not to mention, Ford's are ugly as hell. And I say that as a Ford driver.
 

DesotoCountyDawg

Well-known member
Nov 16, 2005
22,517
10,255
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A 6.7 Powerstroke engine and Allison transmission is the heavy towing dream team. But I'd say Duramax is much closer to Powerstroke than the Ford transmission is to Allison. If I went diesel, GMC is the choice.

Not to mention, Ford's are ugly as hell. And I say that as a Ford driver.
The only issue I have with Ford is they can’t keep a quiet cab. Get about 40,000 farm miles and all you hear is shít rattling in the doors and wherever else.
 
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BoDawg.sixpack

Well-known member
Feb 5, 2010
4,424
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My 2013 Duramax had the faulty fuel pump that disintegrated. Had to have a full fuel system replacement. My 2018 had a bunch of issues with the DEF. I have a 2021 with almost 100,000 miles and knock on wood I’ve had zero issues.
None of them were a problem free, but if you factor in the cost of a used or new vehicle, the ability to work on it yourself, the price of parts, the price of insurance and the overall feature set, the model years of 2010-2012 is going to be the sweet spot.
 
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Ranchdawg

Well-known member
Dec 13, 2012
3,214
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The only issue I have with Ford is they can’t keep a quiet cab. Get about 40,000 farm miles and all you hear is shít rattling in the doors and wherever else.
My 2014 F350 has 178,000 miles on it and the cab is quiet as a mouse. Smooth ride as well.
 

Dawgbite

Well-known member
Nov 1, 2011
6,319
4,889
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My neighbor had a shop specializing in diesel pickups, retired now, but he said that Dodge had the best engine but the rest of the truck was crap. The GM Duramax was a good motor but a ***** to work on. The Allison transmission was the gold standard and nothing else compared. Fords put his kids through college and supported a very expensive racing habit. When he was still in business he said he hoped Ford never quit making diesel trucks. He drives a GMC.
 
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Drebin

Well-known member
Aug 22, 2012
17,028
14,270
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As a rule, buy a diesel if you need one. They are built for towing and driving long distances, not short empty trips around town. I don't know how much you drive, or how important saving a little here and there is, but I would guess the increased mileage vs the extra expense of maintaining a diesel (def, higher fuel prices, expensive maintenance) will make the savings negligible. If it's mostly around town you may be dealing with frequent regens and it will drive you nuts. Cold days are fun too.

I pull a 9,000 lbs RV in the Rockies and went with a gas burner over diesel in my 3/4 ton. I sacrifice a bit of easy towing up Teton pass but otherwise it was a no brainer. Most of my driving (hours not miles) is running around town. Even when I tow the mileage is only 2-3 mpg lower than it's diesel equivalent which is more than made up for with cheaper fuel. It also gets cold where I am and below 15°-20° you have to worry about fuel gelling.

If I were looking at GMC's and I cared about moderate or greater towing and/or acceleration, I would just go 6.2 gasser and sleep like a baby. I'd bet it's the single best 1/2 ton truck engine on the road today. But if you put 30k of highway miles a year on a truck and don't like the temptation of a big V8 under your heavy foot, the 3.0 may be your answer.
This is what I have. 2024 Sierra with the 6.2. Better gas mileage than the 5.3, and very little degradation while towing. That 6.2 engine is badass.
 

J-Dawg

Active member
Mar 4, 2009
2,161
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Not saying you won't get a good one, but these things have issues.
Every modern vehicle has issues outside of the known reliable ones, and even the recent model of those have issues. Crap parts and crap labor across the board.

I have a 24 z71 with the 3.0, 15k miles so far. I really like it. Fuel mileage out of this world. Really like being able to tote a side by side semi-regularly without constant jarring and downshifting going up and down hills.
 
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