Duramax Diesel Engine Production Halted for the Rest of 2021

Photo courtesy GM Authority

It's been a rough year for automakers, but especially for GM. Semiconductor shortages have hit all of the Big 3 automakers, causing production disruptions. GM seems to had more than its share of woes. 

In August we wrote about how strong the demand has been for diesel trucks, though at the end of this article we referenced a temporary halt to production that was announced. That ominous warning evolved quickly to a more serious concern, as GM was forced to change its tune. The temporary parts shortage will impact the engine more than initially expected. The temporary parts shortage would have a bigger impact on the engine than initially expected.

Last week news broke that production had been halted for the rest of the year on its 3.0L LM2 GM Duramax diesel engine. The article does not explain where the derailment took place. Rather it takes advantage of the bad news to remind us of its features and applications.

The LM2 Duramax diesel is assembled in Flint, Michigan. It has been one of the options for their full-size half-ton pickups and full-size SUVs. These would include the Chevy Silverado 1500, GMC Sierra 1500, Chevy Tahoe, Chevy Suburban, GMC Yukon and Cadillac Escalade.

If you ever attend the SEMA Show in Las Vegas, you'll find that GM is not only proud of its cars but also of its engines. The engines are set on pedestals in the massive booth  that historically sprawls in the center of the main hall. They're impressive.

According to the story in GM Authority, "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 halting of Duramax diesel engine production wasn't GM's first black eye this year. In July GM announced a recall for 410,019 trucks due to faulty roof rail airbags. The problem was related to moisture issues that might cause the inflator end cap to detach from the inflator, or cause the inflator to rupture. The 2015-2016 Chevy Silverado 1500 and Chevy Silverado HD, as well as the 2015-2016 GMC Sierra 1500 and GMC Sierra HD were the model years impacted. 

All this safety equipment can be a blessing when you need it. For manufacturers dependent on suppliers, it's just one more thing that can go wrong. In addition to an army of laborers, they are required to have a battalion of lawyers as well.

You will find the full story here.

Enjoy the holiday. We'll be back tomorrow.

Demand for Chev Tahoe and Suburban Diesels Is Growing

How many manufacturers of full-sized SUVs offer a diesel engine alternative? Toyota does not. Nor does Nissan. And neither does Ford. GM alone seems to own this space with a trio of large SUVs -- the Chevy Tahoe, Suburban and the GMC Yukon. GM has evidently identified an unmet need that its competitors have neglected, or simply or created a demand that consumer have been waking up to.

According to the article in GM Authority, when GM made a decision to insert its 3.0-liter I-6 LM2 turbo-diesel Duramax into their 2021 Chevy Tahoe and 2021 Chevy Suburban, both models saw an increase in orders for the diesel engine option. And that is the point this article strives to bring home.

Whereas gasoline-powered full-sized Tahoe and Suburban SUVs still garner more than 90 percent of sales, the story is about the significant growth taking place in the diesel category. Sales numbers reflect the highest take rates since the Duramax became an option.

What is it that is causing this increased interest in the full-sized diesel SUVs? Some surmise that the SUV body styling is preferred over the Chev Silverado 1500 or GMC Sierra 1500, which both offer the same engine. There is certainly a place for each in the lineup. Different strokes for different folks, as they say.

The article proceeds to outline the special characteristics of the 3.0-liter LM2 Duramax engine, which features a duel overhead cam (DOHC) configuration and direct injection, enabling it to produce 277 hp at 3,750 rpm with 460 pound-feet of torque at 1500 rpm. For it size the fuel economy looks good, too. Both are "significantly more efficient" than their gasoline-powered counterparts.

When it comes to towing, the Tahoe diesel is able to tow more than four tons or carry a max payload of 1717 pounds. The Suburban likewise can tow four tons and carry a payload of 1,625 lbs. These are essentially workhorses dressed in their Sunday best.

As you might expect these brands have been keeping pace with the stylish requirements of a futuristic contemporary vehicle. Check our this interior shot of the cockpit. It's NASA Mission Control for civilians. 

Without a doubt the bottom line in this story is that diesel engines are being embraced by a broader portion of the market. The benefits have been increasingly recognized, and sales numbers are confirming it.

The full story includes a few pricing details. And lots more photos. You can find it by clicking this link.

The 2021 GMC Yukon Denali: This Diesel Might Surprise You

With 2020 behind us, the economy has begun showing serious strength in a variety of ways. Live, in person diesel events are happening again and SEMA has announced that SEMA registration is open for this year's show in Las Vegas. Over 1500 companies are already registered.

On April 30 Cars.com had an interesting story by Aaron Bragman titled "Can the Mammoth GMC Yukon Denali Get Good MG With a Diesel Engine?" I like headlines with questions. The word "mammoth" adds a dimension of intrigue. If he left that word out of the title it would not be the same. with the word inserted it suggests, "Can something this massive get good MPG?" 

Bragman begins with a little background that many of us are familiar with. 40 years ago GM offered diesel engines in its big SUVs. More recently, diesels are back, this time with a turbo-diesel 3.0-liter Duramax six-cylinder engine as an option on some of its vehicles. Included in the 2021 catalog are the Chev Tahoe/Suburban and GMC Yukon/Yukon XL. 

"Diesels are often renowned for their stump pulling torque," he writes, as well as their "fuel-sipping frugality." For this reason, Bragman has set up some tests to see how well these attributes hold true in the latest and greatest Yukon.

Before heading into the meat of the matter, we're treated to a description of the interior. Like many of the latest pickups and SUVs by all the manufacturers, efforts have been made to make these machines as comfortable as a dream. More spacious, more luxurious. And under the hood we have a diesel power plant that delivers 277 horsepower with 460 pounds-feet of torque driving a smooth-shifting 10-speed automatic transmission and four-wheel drive.

What Bragman is intending to do here is take the Yukon for a long drive that will involve city, suburban and open highway routes, then compare his results with what the EPA has rated the vehicle at. Before sharing his ride with us, he spells out the expectations with a specificity that lets us know where things stand. This is not his first rodeo. He has a standard 200 mile loop that he drives, and a standard procedure of having the tire pressure set at the manufacturer's recommendations, windows closed and climate control with A.C activated. There are no segments where he does drag racing and his speed is maintained within 5 mph of the posted limits.

Unfortunately, one variable that he has no control over did interfere in his first attempt. Wind gusts up to 45 mph were on and off again to such an extent that he had to abort the mission. The second attempt took place on a placid, sunny day, with satisfying results. 

The Results
Even with its massive weight (5800 lbs) the Yukon Denali 4WD delivered impressive number. The EPA rated it to get 22 mpg but Bragman's results were significantly better. While highway cruising his trip computer showed he was getting more than 30 mpg. The overall numbers when tallied showed he had achieved 27.9 mpg on the 206 mile course. When he refilled the tank, the fuel economy appeared to be 26.9 mpg which was 5 mpg better than its EPA rating.

To Bragman's big surprise, the diesel engine option is $1500 less than the V-8 for this Yukon. Fuel economy savings and a better price as well? What's there not to like?

Well, there are a couple tradeoffs, he says in his closing paragraph. You still know it's a diesel engine there because of the noise. Not a bad big-rig clatter, but something that you can notice. Also, since diesel fuel is currently more expensive at this time, the fuel economy comparison isn't entirely apples to apples. Nevertheless, 65% better fuel economy makes up for a lot compared to the V-8 engine. 

Bottom line: There is much to like in the 2021 Diesel-powered GMC Yukon Denali. 

Read the full story here: https://rb.gy/of5t4m 

Electronics and Sensors: A Blessing and a Curse

The degree to which technology's tentacles have reached into our lives is quite amazing. Getting our vehicles to run at optimal performance is no longer just a matter of turning wrenches, but involves complex wiring diagrams as well. Sensors and brain boxes talk to one another and we just let it happen. Every year we have more whistles and bells on our devices and, let's face it, our diesel truck is just another device.

I remember when my key fob stopped functioning to open and lock my doors. I didn't know why, until one day I discovered that these fobs are battery powered. All I needed to do was change the battery, an answer I discovered only by accident. (Mentioned it in passing during a conversation with a friend.)

There are other kinds of niggling annoyances that aren't so common. For example, what happens when your radio won't turn off? That's what happened to a fellow with the handle Rescue7 who shared this problem on the Duramax Forum. He described his issue like this: 

Recently on my 07 GMC 2500 HD Classic, my radio doesn't turn off when I stop the engine, remove the key & open the door - as it always has always performed in the past? Now the radio just stays on as if on a timer & will time out after 5-10 min.

As you can imagine, he says he doesn't like walking away from his truck while the radio is still on. And I can't blame him.

Fortunately, a former GMC tech named GMAXfirefighter stepped up to the plate to help him walk it through. First, he needed to get the specifics of what was going on. After a series of back and forth posts, there were enough clues to zero in on the real issue and a solution was found.

Ugh. Fortunately, it's not only the Internet of Things that has been getting connected, but people can get connected as well, through forums and other online communities. In short, if all this high tech occasionally leaves you frustrated, you're not alone. 

But solutions aren't far away either.  We have a list of forums and other resources here in the right hand column. Links to forums are below, or you can just reach out and Ask Jake. If he doesn't have an answer, he'll point you in the right direction.

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Source: https://www.duramaxforum.com/threads/radio-wont-turn-off.1009784/