Duramaxby Kevauto -CC-BY-SA-4.0
The Duramax V8 engine is a 6.6-liter Diesel engine produced by DMAX, a combined effort between General Motors and Isuzu.
The Duramax debuted in 2001 as the successor to the 6.2L and 6.5L Detroit engines. It proved to be a powerful and great contender in the light diesel market. Over the years, the engine has gone through several upgrades and improvements to ensure GMC and Chevrolet pickup trucks perform better than their competition.
In this post, we’ll tell you which Duramax years to avoid and which one to go for if you’re looking to buy a usedChevyorGMCtruck. This information is based on the number of complaints filed by users concerning the different model years. Let’s dive in.
Quick Answer: Avoid Duramax Year Models 2001-2010
The Duramax has a long history. We recommend avoiding any GM vehicle equipped with the 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, and 2010 Duramax engines. In short, the newer model years show improved performance.
The first engine was the 6.6L Duramax LB7 used in the 2001 – 2004 Chevrolet Kodiak, Chevrolet Silverado, GMC Topkick, and GMC Sierra HD. It was the simplest in the lineup because it did not have a diesel particulate filter (DPF) or exhaust gas recirculation (EGR). These came later.
The Duramax LLY took over from the LB7 in 2004. It came in the Chevrolet Silverado, Hummer H1 Alpha, and the GMC Sierra until 2005. GM then introduced the Duramax LBZ for the 2006 – 2007 Chevrolet Silverado HD, Chevrolet Kodiak, Chevrolet Express, GMC Sierra, GMC Topkick, and GMC Savanna.
The last engine on our list that we also recommend avoiding is the Duramax LMM which debuted in 2007 – 2010. It is fitted in the Chevrolet Kodiak, Silverado HD, Express, GMC Topkick, Sierra HD, and Savanna. Keep reading to find out the specific issues that plague these Duramax model years.
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Which Duramax Year Modes Are Safe to Buy Used?
According toGM Authority, up to 11 types of Duramax engines have been produced globally since 2001. They include a wide range of eight, six, and four-cylinder options in V or inline (I) configurations. This means that there are plenty of engine choices to pick from.
Earlier Duramax engines were characterized by a couple of inevitable problems that eventually cost owners in repairs. If you’re looking for an engine that won’t trouble you much, we recommend the following Duramax year models:
- 2010 – 2017 Duramax LGH
- 2011 – 2016 Duramax LML
- 2011 – 2021 Duramax XLD25
- 2012 – 2021 Duramax XLD28
- 2014 – 2021 Duramax LWN
- 2017 – 2021 Duramax L5P
- 2019 – 2021 Duramax LM2
The Duramax engine received significant changes in 2011 to meet the new emissions regulations. Despite it being more complicated than its predecessors, it is more reliable. The safest Duramax model years you can buy are the models produced from 2011 to 2021.
These include the Duramax LGH, Duramax LML, Duramax XLD25, Duramax XLD28, Duramax LWN, Duramax L5P, and Duramax LM2. These engines go a step further to provide better emissions thanks to a diesel exhaust fluid/urea injection feature. An after-treatment system also allows owners to increase fuel economy using exhaust after-treatments.
The only problem you may experience in these engines is weak tie rods that may go bad when drag racing, off-roading, or sled-pulling. The exhaust after-treatment system/diesel particulate filter also comes with a failure point that can cause problems.
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Which Duramax Years to Avoid?
If you’re looking for fuel economy, reliability, comfort, and power, there are plenty of Duramax engines that you can choose from. This is especially true if you’re in the market for a Chevy Silverado or GMC Sierra younger than ten years old.
Thus, you must know which Duramax years to avoid. We recommend staying away from GM trucks that have the following engines:
- 2001 – 2004 Duramax LB7
- 2004 – 2005 Duramax LLY
- 2006 – 2007 Duramax LBZ
- 2007 – 2012 Duramax LMM
According toDriving Line, if you have a Chevy Kodiak, Chevy Silverado, GMC Sierra HD, or GMC Topkick with the Duramax LB77, it is virtually inevitable that you’ll experience a problem with the fuel injection system. This is especially the case if the previous owner did not follow GM’s protocol to have the injectors replaced under warranty.
As for the Duramax LLY engine fitted in the 2004 – 2005 Chevrolet Silverado, Hummer H1, and GMC Sierra HD, the most common problems that owners experience include overheating when towing and blown head gaskets.
The LBZ is perhaps one of the most desired Duramax engines. It addressed the overheating and blown gasket issues that plague the LLY. However, we recommend staying away from it due to pistons that crack at higher horsepower. Some users also complained about cab corners and rocker panels that rust faster in northern regions due to high humidity and salt.
The Duramax LMM took over from the LBZ in 2007 and was fitted in the Chevrolet Silverado HD, Kodiak, Express, GMC Topkick, Savanna, and Sierra HD until 2010. Like its predecessor, it also suffers from cracked pistons at higher horsepower. The diesel particulate filter also comes with a failure point.
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Common Duramax Diesel Engine Problems
Every engine has its share of quirks, and the Duramax V8 engine is no exception. Here are some of the most common problems across all Duramax years.
- Fuel injector failure:Common with the LB7 Duramax engines, the premature injector failure caused so many headaches for owners. Apparently, the fuel injectors were prone to fuel leaks, leading to fuel dilution. GMC had to recall the issue for this design flaw.
- Water pump failure:The LB7 and LLY engines had problems with faulty water pumps. With a defective water pump, the engine will likely overheat. GMC released a more prominent, redesigned water pump to address this issue.
- Turbocharger oil ingestion:This issue affected the 6.6L Duramax LB7, LLY, LBZ, LMM, and LML engines, so it’s pretty prevalent. According to experts, the PCV design of the Duramax vents excess pressure into the intake. This causes the engine oil to be introduced into the turbocharger.
- Glow plug failure:The LLY and later the LBZ struggled with glow plug failure. The culprit was determined to be the faulty glow plug modules. If left unattended, a catastrophic engine failure is highly likely. Once again, GMC had to issue a recall for this issue.
What’s the Life Expectancy of Duramax Diesel Engines?
While the Duramax engine is truly a marvel of engineering, one of the most common questions about it is its life expectancy. Thankfully, Duramax diesel engines are reliable by default and can last you for hundreds of thousands of miles, especially with proper care and maintenance.
Many Duramax vehicles are still on the road today and still work like new despite passing 100,000 miles. According to many owners, Duramax engines can reach 200,000 with little to no issues. With proper maintenance, Duramax engines can run north of 300k-400k miles. People at theDuramax Forumsclaimed their vehicles had reached 300,000 and even 400,000 miles with just the stock engine. One user even commented on pushing 535,000 miles on his LB7, which is mind-blowing.
The average driver can expect about 200k-300k miles before needing any major repairs. Of course, these numbers will depend on how you use your vehicle and the amount of maintenance you give it. At the end of the day, it’s fair to say that Duramax engines are reliable and long-lasting.
What’s the Life Expectancy of Duramax Diesel Engines?
While the Duramax engine is truly a marvel of engineering, one of the most common questions about it is its life expectancy. Thankfully, Duramax diesel engines are reliable by default and can last you for hundreds of thousands of miles, especially with proper care and maintenance.
Many Duramax vehicles are still on the road today and still work like new despite passing 100,000 miles. According to many owners, Duramax engines can reach 200,000 with little to no issues. With proper maintenance, Duramax engines can run north of 300k-400k miles. People at theDuramax Forumsclaimed their vehicles had reached 300,000 and even 400,000 miles with just the stock engine. One user even commented on pushing 535,000 miles on his LB7, which is mind-blowing.
The average driver can expect about 200k-300k miles before needing any major repairs. Of course, these numbers will depend on how you use your vehicle and the amount of maintenance you give it. At the end of the day, it’s fair to say that Duramax engines are reliable and long-lasting.
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FAQs
What years should you avoid Duramax? ›
Quick Answer: Avoid Duramax Year Models 2001-2010
The Duramax has a long history. We recommend avoiding any GM vehicle equipped with the 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, and 2010 Duramax engines. In short, the newer model years show improved performance.
Early LML Duramax trucks 2011-2012 have well-documented issues with Nitrogen Oxide (NOx) sensors that are a part of this SCR system. Other issues have also occurred regarding the DEF system. Emission repairs are often expensive! Replacing the DPF alone can cost thousands of dollars!
Is a 2012 Duramax a LML? ›LML. The 6.6L RPO LML (VIN code "8") is the 2011–2016 version of the Isuzu/GM Duramax V8 diesel engine. It is a further advanced version of the LMM engine with the majority of the changes addressing a required drastic reduction in engine emissions.
What is considered high mileage for a 6.6 Duramax? ›What Is Considered High Mileage for a Duramax Diesel Pickup Truck? Duramax is General Motors' brand of diesel engines for GMC and Chevy trucks. They're well-known for their reliability. Duramax trucks above 300,000 miles are usually considered high mileage.
What year is the best Duramax to buy? ›2006-2007 2500 & 3500
With arguably the best plug-and-play horsepower potential (on top of 360 horsepower being offered right out of the box), the last of the (essentially*) emissions-free engines, and a stronger, six-speed Allison to back them, the LBZ Duramax has a lot going for it.
It is often known that the 2004.5-2005 LLY Duramax Engine year models have temperature issues. This usually leads it to being the most prominent of the Duramax models for having gasket failures.
Is the LML the best Duramax? ›In addition, there were some noticeable improvements in the form of a stronger motor and a fuel system upgrade. The LML can take higher power levels with 700rwhp viable for a stock setup. Here we explain why it's one of the best Duramax engines yet.
What is the difference between LML and L5P? ›To put this all-in perspective, the L5P puts out 48 MORE horsepower than the LML and 145 lb. ft. more torque than its predecessor. At all engine speeds, in all conditions, the L5P simply trounces the LML.
Does a 2014 Duramax have def? ›Duramax (GMC & Chevy) trucks have the DEF filler under the hood on the passenger side, also with a blue cap.
What is the most reliable Duramax engine? ›The LBZ also offers excellent tuning and modification potential, which is extremely attractive to most diesel enthusiasts. Finally, the LBZ is the last generation of Duramax without emissions control parts, which gives it superior reliability. For those reasons, the LBZ is our choice for the best Duramax engine.
Is the 2011 Duramax a good engine? ›
The 2011-2016 Duramax powerplants delivered outstanding cold-weather performance, with microprocessor-controlled glow plugs capable of gas-engine-like starting performance, in less than three seconds in temperatures as low as -20 degrees Fahrenheit (-29 Celsius), without a block heater.
How many miles does it take to break in a Duramax diesel? ›And every two weeks take it out on a 100 mile trip, (50 miles one way, then back). USE the cruise control to teach the computer the lay of the land,BUT vary it as your cruising. Set it at 70 for 20 miles then bring it down to 66. Then turn it off for the last 40 miles and let it learn your foot.
What's better Duramax or Cummins? ›Duramax offers more horsepower, but Cummins provides the most torque. Depending on the truck, a Cummins engine can provide up to 1,000 feet-pounds of torque.
Which is better Cummins Duramax or Powerstroke? ›The Power Stroke has more horsepower but slightly less torque, while the Cummins has the opposite. However, as noted by AutoWise, the Power Stroke ultimately produces more horsepower, which is a better indicator of engine strength in real driving situations.
Is it bad to let diesel idle? ›Unnecessary idling wastes fuel, causes air pollution and increases engine wear. An idling diesel engine produces much higher emissions than it would while using the same amount of fuel under load. Extended idling causes a build-up of soot inside the engine and results in a puff of black smoke when the engine revs.
What is the fastest stock Duramax? ›Brett Deutsch's 1969 Chevy C10 currently holds the record for the fastest diesel-powered Pro Stock truck in the quarter mile. Under the hood is this single-turbo LLY Duramax engine.
Which Duramax has injector problems? ›What year Duramax has injector problems? The LB7 Duramax built from 2001 – 2004.5 is known for injector failure. The good news is the replacement injectors you purchase from us incorporate several updates to help prevent repeat failures.
Are 6.6 Duramax reliable? ›Duramax Engines have an excellent reputation for reliability. Each model year is associated with problems, especially when the engines reach 100,000+ miles. However, while Cummins engines may continue to edge out Duramax in terms of overall reliability, Duramax fans love their higher horsepower.
How often do Duramax injectors go bad? ›However, early Duramaxes aren't problem free. The biggest issue with '01-to-'04 and 1/2 LB7 engines is their fuel injectors' propensity to fail, typically before an engine reaches 100,000 miles.
Which Duramax breaks crankshaft? ›Snapped Crankshaft
Not specific to one version of Duramax in particular (ex: LB7, LLY, LBZ, LMM or LML), the problem exists across all generations. The crankshaft usually breaks near the number one rod journal due to a combination of excessive rpm and the large external counterweight.
What is high mileage on a Duramax? ›
As for what's considered high mileage for specific diesel engines? According to Prosource Diesel, anything over 350,000-miles is considered high mileage for a used diesel pickup with a Cummins or Duramax engine under its hood. Anything over 350,000-miles is also regarded as high mileage for a Powerstroke diesel engine.