3.0L LM2 GM Duramax Diesel Engine Production Halted Through 2021

Late August, GM Authority reported that production of the 3.0L LM2 turbo-diesel Duramax engine was temporarily halted due to a supplier issue. Now, GMA has learned that production of the engine will be idled for the remainder of the 2021 calendar year.

The 3.0L I6 LM2 Duramax diesel engine is assembled at the GM Flint Engine Plant in Flint, Michigan. It is offered as an option in GM’s full-size half-ton pickup trucks and full-size SUVs, including the Chevy Silverado 1500, GMC Sierra 1500, Chevy Tahoe, Chevy Suburban, GMC Yukon, and Cadillac Escalade.

The LM2 engine features a straight six configuration with a DOHC valvetrain, 84mm bore, and 90mm stroke, with a 15.0:1 compression ratio. The block and heads are made of aluminum, with a forged steel crankshaft and forged rods. The pistons are made from hypereutectic cast aluminum alloy, while the cylinder liners are made from iron.

The fueling system uses a common rail with direct fuel injection. Induction air is chilled using a liquid-to-air intercooler.

Output of the LM2 is rated at 277 horsepower at 3,750 rpm and 460 pound-feet of torque at 1,500 rpm in all of the aforementioned vehicles. For the 2019, 2020 and 2021 model years, the LM2 is mated to GM’s 10-speed automatic transmission, no matter the vehicle application.

While the healthy amount of low-end torque make it a great option for towing duties, the turbocharged 3.0L I6 LM2 Duramax diesel is also quite fuel efficient. For example, when equipped in the 2021 Chevy Suburban with rear-wheel drive, the LM2 delivers 21 mpg in the city, 27 mpg on the highway, and 23 mpg combined, with an annual estimated fuel cost of $1,650. By comparison, the 5.3L V8 L84 gasoline engine, which is the base engine in the 2021 Suburban, is rated at a much less substantial 16 mph in the city, 20 mph on the highway, and 18 mph combined.

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Vince grew up in a GM family, likes manuals, and thinks this is the golden age of the automobile.

Vince Brown

Vince grew up in a GM family, likes manuals, and thinks this is the golden age of the automobile.

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    • 2 sentences about the story and then 4 paragraphs of fluff.

      How about telling us WHY it's not being produced or, if you don't know, just make the story a quick headline or bulletin.

      But that's not how the internet works is it?

      • You should be thankful that they’re reporting on it and are first in doing so. GMA doesn’t owe you anything but you probably owe them a thanks. A little gratitude goes a long way.

        • I wish they WERE reporting on it. The above article states something, and then offers no backup, no information at all.

          I don't claim to be an "Authority" like this site does. It's a good site but this article is crap.

        • GM Authority routinely posts super vaque articles without any kind of proof of what they're saying.. they don't do any kind of research and pretend like people should just automatically believe them just because of their name..

          They throw crap against the wall and see what sticks.. and the vast majority of these people just soak it up..🙄🙄

        • I bought one two weeks ago September 20 2021. Driving in town and the ck engine came on the message board came on stated the exhaust filter and to keep driving so I got on the freeway would hardly run no power so I drove about twenty mile the message cleared but the ck engine light was on ran like crap and the engine was noisy sound like the exhaust was stopped up 180. Miles on it. Any ideas.

          • Welcome to the world of diesel and 8 large exhaust systems.
            My advice sell it before the emissions warranty expires.

          • Had my engine replaced at 70,000 miles and now it’s back to making the ticking sound it did before it dropped the #3 exhaust valve

          • I have replied to someone about my truck the intake broke was in the shop seven days they finally took the intake to a metal shop and welded it. I am getting 26.7 mpg and the best was 27.4 hoping for 30 mpg. running great 4x4 Silverado

  • Strange halt. For the next four months? Piece part(s) from vendor delay for the next 16 weeks? There is something to this situation that is not being told.

    Possible reliability / performance situation?

    Please explain.

    • 150k mile belt that takes 22 bolts and 6hrs to change? What DOHC vehicle do you drive? You know where I am going.....talking out of both sides of your mouth if you drive any foreign moniker.

      • That's the thing. These are engines that are designed by Europeans for a European luxury sedan. The comparable EcoDiesel on the Ram was put in the European Chrysler 300 and several Maseratis. So a timing belt change at 150k is reasonable there (particularly since European vehicles are driven significantly less per year, so 150k is lifetime).

        However, it's being compared to American V8s because it's being put in an American truck, and that's why people are calling the design out.

      • I’ve had nothing but problems with mine. New turbo new wiring harness and then new engine now the transmission is giving me problems

    • Bill, ordered my 2022 limited RST with the LM2 back on Oct 1st. Got an inside contact at the Roanoke plant and he told me this morning that the LM2's are in many of the trucks being built...

    • I bought one two weeks ago September 20 2021. Driving in town and the ck engine came on the message board came on stated the exhaust filter and to keep driving so I got on the freeway would hardly run no power so I drove about twenty mile the message cleared but the ck engine light was on ran like crap and the engine was noisy sound like the exhaust was stopped up 180. Miles on it. Any ideas.

      • hola leon buenos dias como tecnico en diesel ,llevo trabajando 21 años en los diesel aqui en europa el motor ese que han fabricdo ultimamente no es malo he leido sobre el el problema lo tienes porque recicla mucho el motor ha bajas revoluciones ,por la conduccion que haces date cuenta que es un motor diseñado con una compresion de 15.1es algo de admirar aqui en europa no se fabrican con esa compresion por las regeneraciones que hace el motor en marcha y se encienda la luz de contaminacion te puedo dar un consejo como tecnico llevalo en marchas mas cortas si es automatico en modo secuecial asi el no recicla tanto y el filtro de particulas trabaja bien ya que lleva inyector scr para el oxido de nitrogeno para limpiar el hollin que expulsa a la calle ,se evita que se encienda la luz ,si vas en capital llevalo en 3. velocidad y en carretera en 5 velocidad si vas ha 120km por hora y asi hevitas ir al taller y crea menos carbonilla en los colectores de admision ya que es un motor con tecnologia inteligente un saludo y me dices y o ponle un gas-oil bueno para evitar suciedad en las camaras de combustion

  • Really hope this is not accurate news. I have my Silverado 2022 Limited already ordered... I do not want to order a V8...

  • question is it the calendar year OR THE 2021 MODEL year .......aren't the 2022's on schedule to start building Oct 4th.....that would sound more plausible

  • A unidentified part shortage for 4 months?
    Sounds like they found a problem and are stopping the recall bleeding.

  • The article states 2021 calendar year...that's ending December 31, 2021. Not model run year.

    What is truly going on here? Vendor blame is a traditional finger pointing out. Please detail.

    From a GM fan who loves diesel engines from the 6.2 in a Suburban, to a 6.5 in a Suburban, and now waiting for my 3.0 in a Suburban. ???

    BTW: I currently have 514+K on my 1998 GMC Suburban 2500. All original engine guts, block and heads. Love it. Change engine oil every 5K with Mobil One high mileage synthetic 10W 40 at $22.00 a jug at Walmart, and use K&N oil filter for $11.00 at Walmart.
    Takes a jug and a third of Mobil One 10W 40 synthetic high mileage. Getting 27 mpg approx. at 1900 ram, 64 mph approx. Minimal to no oil consumption.

    Let's get it together lowercase gm. Alfred P. Sloan is spinning in his grave. Let's make America Great Again.

    • If you want to "make America great again" then don't buy this engine. Italian designed with European vendors (same group that worked with Fiat to make the EcoDiesel). Even GM has said that it has no commonality with the 6.6L Duramax.

      You talk about oil: this motor uses European low-viscosity grades, 0W-20. Try to find 0W-20 diesel in the US: there's two approved brands, AC Delco and Mobil 1 ESP X2 0W-20. Go try to find either at Wal-Mart.

      Also, to make it cheap, they don't use a hydrocarbon injector for regens like the 6.6L, it uses post-injection, so it dilutes the oil.

      • GM divested of the Italian joint venture years ago without a single engine going in a GM product. I thought the 30 was a GM design they did since they pulled out of that deal? The Ecodiesel is a great engine except the 2014-2015 original EGR system.

        • The joint venture was broken up when Fiat bought Chrysler. Both sides retained their parts, it was not divested. GM's share, GM Powertrain Torino, continued to design Opel diesels and this engine. GM finally sold it in 2020 as part of the European pull-out.

          • Ecodiesel is a V6 and GM is an I6. Different injectors and EGR systems. Billed as a clean sheet design at introduction. If any parts was retained it was the stand the engine ships on.

          • I never said it was the same as the EcoDiesel. I said it was the same group of engineers in Turin Italy that worked on both.

            The EcoDiesel needed to be a V6 so they could fit it in a number of sedans.

          • A couple of decades back Daimler-Benz was in the hunt for expansion in North America. They wanted established nameplates with a large and established dealer network. Daimler purchased Detroit Diesel from Roger Penske, White Motor in Cleveland, Ohio, and Chrysler. Daimler was on a feeding binge.

            Daimler wanted Chrysler due to their hot design shop at the time, which was the most successful and innovative in the industry during that era. The honeymoon was short lived due to infighting, politics, and jealousy between American and German management.

            The Germans tried to make a go of it by bringing in Dr. Z, but things didn't work out. Chrysler was unloaded to an independent investment group of non car people and floundered until the financials were to the point where it could fetch a reasonable sale.

            Chrysler went for sale again and Fiat grabbed it. Fiat like Daimler was in the hunt for North American business expansion. Fiat having previously purchased what was left of Allis-Chalmers. Fiat tried to make a go of A-C but floundered and failed, with the long slow painful death of Fiat-Allis.

            Fiat in a move to save and maintain it's position and investment in Chrysler with the dramatic changes occurring in the auto industry went into a combined joint venture collaboration with Renault to form Stellantis. Fiat and Renault have been technical laggards in automotive engineering. Their combination in their business planning will hopefully provide planned strength to overcome the fierce Asian, American and German automaking competition.

            Stellantis does have a winner with Jeep and RAM, and their relationship with Cummins.

            Cummins has developed into the best stand alone Diesel engine maker in the business alongside Caterpillar. Detroit Diesel is now playing catch up again, but has a strong dealer network which was the main factor for Daimler-Benz initially wanting it.

          • Agree with most of your post. However....Detroit Diesel is not playing 'catch up'...their engines are only available in Daimler based trucks (Freightliner, Western Star etc) and Daimler has a market share around 40% in North America. Caterpillar couldn't make a 2010 emissions compliant diesel for on road trucks and exited the truck engine business in 2010 (and their emission compliant engines between 2007 and 2009 were horrendous). Cummins continues to plod along making pretty good stuff and are really the only independent engine manufacturer available in North American (big) trucks. You basically have 2 choices now when you buy a big truck...Cummins or the in house branded engine (Detroit/Daimler, Paccar/Pete-KW, Volvo-Mack/Volvo-Mack, International(MAN)- International). It sucks because it took a LOT of the competition and innovation away.

      • You really know nothing about this truck. I have owned a 2020 RST Z71 that now has 35,000 miles. Truck has been nothing short of awesome. It regularly gets 26-30 mpg. It gets 19-20 mpg towing my Camaro to the racetrack. Its driveability is spot on. It is perfect for what it was designed for. It is not a 6.6 nor was it designed to be an HD truck and tow 12,000lbs. It was a clean sheet design here in the US. I change my own oil. No big deal in getting Mobil 1 for it. It is by far the best truck I have owned.

        • Hi I have a 2021 IL 6 diesel truck 4 wheel drive and the intake broke. in the shop for seven days they finally took it to a metal shop had it welded it is getting 26.4 mpg and best is 27.6 I hoping for 30 mpg 1000. Miles on it. Leon

      • jwl: Your local Walmart is ripping you off at $31.00 for a 5 quart jug of Mobil One synthetic high mileage 10W 40 engine oil. At Nevada Walmart's the retail price is approx. $22.00. Do you live in California, where you have a regional inflation and regulations?

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