If you want to know the best and worst year models of Duramax engines, then you have come to the right place.
The joint venture between Isuzu and General Motors (officially known as DMAX) in Moraine, Ohio, brought about the Duramax diesel engines that consist of eight-, four-, and six-cylinder engines.
The Duramax engines came in both V and inline (I) configurations, with most of their applications being in Chevrolet and GMC vehicles.
The older models are simpler but come with lots of complications such as overheating, head gasket failure, weak tie rods, and water pump failures, just to mention a few.
The new models improved upon their predecessors, but they are more complex.
We will look at the various year models of the prolific Duramax engines.
Our focus will be to highlight their features to show you their weaknesses and strengths.
Stick around to learn which Duramax engines to avoid and which ones to buy.
Best Duramax Engine: Specs Comparison Chart
Enter the engine model in the Search Box. E.g. LB7
| Engine | Horsepower | Torque |
|---|---|---|
| LB7 | 300 hp @ 3,100 rpm | 520 lb-ft @ 1,800 rpm |
| LLY | Auto trans: 310 hp @ 3,000 rpm Manual trans: 300 hp @ 3,000 rpm | Auto trans: 605 lb-ft @ 1,600 rpm Manual trans: 520 lb-ft @1,600 rpm |
| LBZ | 360 hp @ 3,200 rpm Van: 250 hp @ 2,500 rpm Medium duty: 310 hp @ 3,000 rpm | 650 lb-ft @ 1,600 rpm Van: 460 lb-ft @ 1,600 rpm Medium duty: 605 lb-ft @ 1,600 rpm |
| LMM | 365 hp @ 3,200 rpm | 660 lb-ft @ 1,600 rpm |
| LML | 397 hp @ 3,000 rpm | 765 lb-ft @ 1,600 rpm |
| LGH | Express/Savana Vans: 260 hp @ 3,100 rpm Silverado/Sierra chassis cab: 335 hp @ 3,100 rpm | Express/Savana Vans: 525 lb-ft @ 1,600 rpm Silverado/Sierra chassis cab: 685 lb-ft @ 1,600 rpm |
| L5P | 445 hp @ 2,800 rpm | 910 lb-ft @ 1,600 rpm |
| L5D | 350 hp @ 2,700 rpm | 700 lb-ft @ 1,600 rpm |
| XLD25 | 163 hp @ 3,600 rpm | 280 lb-ft @ 2,000 rpm |
| XLD28 | 200 hp @ 3,600 rpm | 360 lb-ft @ 2,000 rpm |
| LWN | 181 hp @ 3,400 rpm | 369 lb-ft @ 2,000 rpm |
| LM2 | 277 hp @ 3,750 rpm | 460 lb-ft @ 1,500 rpm |
Best Duramax Engine Year Models Safe To Buy
Newer engines will not trouble you as much as the old models.
When looking for a reliable machine, the phrase ‘old but gold’ does not apply.
The first Duramax models, from 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, and 2010 (apart from LGH) were faced with lots of issues that will cost you a lot in terms of repairs and maintenance.
Moreover, these year models are not safe to use as newer ones due to new features such as DEF (diesel exhaust fluid) and DPF (diesel particulate filter) systems implemented in the 2010 to 2021 Duramax engines.
You will also find out that the efficiency of Duramax LGH to Duramax LM2 is higher due to the combination of efficient systems and computerized tunes.
New emission regulations were also implemented in the Duramax engines in 2011 and later.
The improvements made the machines more complicated but safer and drivable for longer.
Emissions systems were improved in the later models by using diesel exhaust fluid and urea injection features.
Another advantage of the new 2011 to 2021 models is their use of after-treatment systems that enable vehicle users to tune the fuel economy.
With this system, you can increase your vehicle’s fuel economy by adjusting the exhaust after treatments.
The best Duramax diesel engine year models that are safe to buy include:
- 2010 – 2017 Duramax LGH
- 2011 – 2016 Duramax LML
- 2011 – present Duramax XLD25
- 2012 – present Duramax XLD28
- 2014 – present Duramax LWN
- 2017 – present Duramax L5P
- 2019 – present Duramax LM2
Duramax Engine Year Models To Avoid
You should avoid buying Duramax engine models from 2001 to 2010. Engines from this era are full of mechanical issues as well as durability limitations based on their build quality, the materials used, and available features.
Duramax engines such as the Duramax LB7 and Duramax LLY have frequent issues that involve the:
- fuel lift pump,
- fuel injectors,
- water pumps,
- head gasket,
- tie rods, and
- turbo inlet manifold, just to mention a few.
It will cost you a lot to repair and maintain these engines, and their lifespan is short even if you get one new.
Avoid Duramax engine year models from 2001 to 2010, including:
- 2001 – 2004 Duramax LB7
- 2004 – 2005 Duramax LLY
- 2006 – 2007 Duramax LBZ
- 2007 – 2010 Duramax LMM
Duramax Engine: All Year Models, Applications, and Common Problems
Enter the engine model in the Search Box. E.g. LB7
| Engine Model Years | Applications | Common Problems |
|---|---|---|
| 2001-2004 LB7 | 1. Chevrolet Silverado 2500, 3500 (2001-2004); 2. GMC Sierra 2500, 3500( 2001-2004); 3. Chevrolet Kodiak C4500, C5500 (2003-2004); 4. GMC TopKick C4500, C500 (2003-2004). | 1. Issues with the fuel injector; 2. No fuel lift pump, water pump leaks; 3. Overheating; 4. Head gasket failures; 5. Leaking O-rings on the fuel filter housing; 6. Allison 1000 transmission limp mode; 7. Broken or snapped tie rods; 8. High horsepower applications. |
| 2004-2005 LLY | 1. Chevrolet Silverado 2500 HD, 3500 HD (2004-2006); 2. GMC Sierra 2500 HD, 3500 HD (2004-2006); 3. Chevrolet Kodiak (2004-2006); 4. GMC TopKick (2004-2006); 5. Hummer H1 (2006); 6. GMC Savana (2006). | 1. Head gasket failures; 2. Water pump malfunctions; 3. Overheating of the engine; 4. No factory lift pump; 5. Turbo inlet manifold failures; 6. Injector harness chafing; 7. Glow plug failure; 8. EGR valve problems; 9. Fuel pressure’s relief valve malfunctions; 10. Suspension and steering problems; 11. Bent rods. |
| 2006-2007 LBZ | 1. Chevrolet Silverado 2500 HD, 3500 HD (2006-2007); 2. GMC Sierra 2500 HD, 3500 HD (2006-2007); 3. Chevrolet Express 2500, 3500 (2006-2007); 4. GMC Savana 2500, 3500 (2006-2007); 5. Chevrolet Kodiak (2006-2007); 6. GMC TopKick (2006-2007). | 1. Cracked pistons; 2. Glow plug failures; 3. EGR problems; 4. Allison 1000 transmission line leaks; 5. Water pump failures. |
| 2007-2010 LMM | 1. Chevrolet Silverado 2500 HD, 3500 HD (2007-2010); 2. GMC Sierra 2500 HD, 3500 HD (2007-2010); 3. Chevrolet Express 2500, 3500, 4500 (2007-2010); 4. GMC Savana 2500, 3500, 4500 (2007-2010). | 1. DPF system and active regeneration malfunction; 2. Leaking transmission lines; 3. Fueling/low fuel pressure; 4. Piston and crankshaft failure; 5. Allison 1000 power limitations. |
| 2010-2017 LGH | 1. Chevrolet Express 2500, 3500, 4500 vans (2011-2016); 2. GMC Savana 2500, 3500, 4500 vans (2011-2016); 3. Chevrolet Silverado 3500 HD chassis cab (2011-2012); 4. GMC Sierra 3500 HD chassis cab (2011-2012). | CP4.2 injection pump failure. |
| 2011-2016 LML | 1. Chevrolet Silverado 2500 HD, 3500 HD (2011-2016); 2. GMC Sierra 2500 HD, 3500 HD (2011-2016). | 1. DEF pump failure; 2. DEF heater problems; 3. CP4.2 injection pump failure and NOx sensor failure. |
| 2017-present L5P | 1. Chevrolet Silverado 2500HD, 3500HD (2017-current) 2. GMC Sierra 2500HD, 3500HD (2017-current) | 1. MAP sensor failure; 2. Allison 1000 transmission limitations; 3. Fuel injector failure, especially injector number 4. |
| 2019-present L5D | 1. Chevrolet Silverado 4500HD, 5500HD, 6500HD medium duty trucks (2019-current); 2. International CV Series medium duty trucks (2019-current). | Air filter failure. |
| 2011-present XLD25 | 1. Chevrolet Colorado S-10; 2. Chevrolet Trailblazer for international markets; 3. Mid-size pickup trucks; 4. SUVs. | No reported significant issues. |
| 2012-present XLD28 | 1. Chevrolet Colorado (2012-current) 2. GMC Canyon (2012-current) 3. Chevrolet Express (2012-current) 4. GMC Savana vans (2012-current) | No reported significant issues. |
| 2014-present LWN | 1. Chevrolet Colorado (2016-current) 2. GMC Canyon (2016-current) 3. Chevrolet Express 2500, 3500 (2017-current) 4. GMC Savana 2500, 3500 (2017-current) | 1. DEF pump failures; 2. Heater and turbo malfunctions. |
| 2019-present LM2 | 1. Chevrolet Silverado 1500 (2020-current) 2. GMC Sierra 1500 (2020-current) 3. Cadillac Escalade (2021-current) 4. Chevrolet Tahoe (2021-current) 5. Chevrolet Suburban (2021-current) 6. GMC Yukon (2021-current) | Weak tie rods (unlikely). |
2001 – 2004 Duramax LB7
Credit: chevytrucks.org
The Duramax LB7 is a Regular Production Option (RPO) code for General Motors that denotes the Duramax engine produced between 2001 and 2004.
The engine consisted of Bosch high-pressure common rail direct injection system incorporated into its 32-valve design.
Its block and head were made of cast iron and aluminum, respectively.
The powerful 6.6L V-8 engine produced 300 horsepower at 3,100 rpm with a torque of 520 lb-ft at 1,800 rpm.
It is the least functional engine of the line-up, but a turbocharger and intercooler make it formidable.
Applications
LB7 Duramax engines are used in the Chevrolet Silverado 2500 and 3500, GMC Sierra HD 2500 and 3500, Chevrolet Kodiak C4500 and C5500, and GMC Topkick C4500 and C500 till early 2004 when they got replaced by their successor, the LLY.
Common problems
The common problems in the LB7 are the most prevalent in the Duramax engines.
Customers have reported issues with the fuel injector that goes bad quickly.
There is no fuel lift pump in the LB7 engines and the water pump leaks.
LB7s also experienced overheating and head gasket failures over a prolonged period of use.
Other issues with the engine include:
- Leaking O-rings on the fuel filter housing;
- Allison 1000 transmission limp mode;
- Broken or snapped tie rods;
- High horsepower applications.
Is It Good Or Bad? Should I Buy It?
Despite its powerful output and sufficient application in GMC and Chevy vehicles, the LB7 is the least recommended engine in the group.
You should not buy this engine lest you end up spending a lot of time at the mechanic shop.
2004 – 2005 Duramax LLY
The Duramax LLY engines took over the Duramax engine category fully by mid-2004.
DMAX improved the injectors due to so many failures in the LB7.
The valve covers were improved to allow access to the fuel injectors without removing the valve covers.
This helped save a lot of labor charges if you were to replace the injectors.
It used the same 32-valve design as well as Bosch’s high-pressure common rail injection.
The compression ratio remained at 17.5:1, improving horsepower (310 hp at 3,000 rpm with automatic transmissions and 300 hp at 3,000 rpm with manual transmissions) and torque (605 lb-ft at 1,600 rpm with automatic transmissions and 520 lb-ft at 1,600 rpm with manual transmission).
Applications
Credit: commons.wikimedia.org
The 6,619-cc turbocharged engine finds its application in the 2004 to 2005 Chevrolet Silverado 2500 HD and 3500 HD.
It was also implemented in the GMC Sierra 2500 HD 3500 HD from 2004 to 2005.
Common problems
Like its predecessor, the LLY did not fall short of many issues.
Despite the upgrades, the LLY engine still had head gasket failures, water pump malfunctions, overheating of the engine, and lacked a factory lift pump.
Other issues included:
- Turbo inlet manifold failures;
- Injector harness chafing;
- Glow plug failure;
- EGR valve problems;
- Fuel pressure’s relief valve malfunctions;
- Suspension and steering problems;
- Bent rods.
Is It Good Or Bad? Should I Buy It?
The LLY was an improvement on the LB7 but still retained a lot of issues that will make it a hard bargain for the current market.
It would be best not to buy the LLY due to its many problems and the lack of essential features like the factory lift pump.
2006 – 2007 Duramax LLY/LBZ
Credit: dieselexperts.net
The 2006 to 2007 Duramax V-8 engines have two VIN codes due to delays in getting EPA certification.
There is Vin 2 and VIN D; VIN 2 is identical to the VIN D but uses the tunings of the LLY.
VIN D was the post-EPA certification model with a computer tune for more power and torque.
Improvements include an upgrade of the primary bearing material, which enhanced durability.
The compression ratio was modified to 16.8: 1 from 17.5:1, and the connecting rod ‘I’ was made thicker for more strength.
The engine was made quieter by the introduction of air induction systems.
LLY/LBZ saw the first use of the 32-bit E35 controller for regulating fuel flow to improve efficiency and reduce carbon emissions.
The LBZ has 360 hp at 3,200 rpm and 650 lb-ft of torque at 1,600 rpm.
For LBZs in vans, the horsepower is 250 at 2,500 rpm and the torque is 460 lb-ft at 1,600 rpm.
In medium-duty vehicles, the horsepower is 310 at 3,000 rpm and the torque is 605 lb-ft at 1,600 rpm.
Applications
The first LLY-inspired model from late 2005 and early 2006 was used in the:
- Chevrolet Silverado HD,
- Chevrolet Kodiak,
- GMC Sierra HD,
- Chevrolet Express,
- 2006 Hummer H1 Alpha, and
- GMC Savana.
The later LBZ was applied in the Chevrolet Silverado HD, GMC Sierra HD, GMC TopKick, and Chevrolet Kodiak.
Common problems
LLY/LBZ engines had more strength and efficiency than any other Duramax engines at the time.
The only common issues in these engines include: cracked pistons, glow plug failures, EGR problems, Allison 1000 transmission line leaks, and water pump failures.
Is It Good Or Bad? Should I Buy It?
LLY/LBZ from 2006 to 2007 is considered one of the most reliable and rugged engines from the pre-emission era.
They are widely sought out because of this and can be a great buy if you are looking for a Duramax engine of this time.
Beware that they have more issues than recent Duramax engines from 2011 to 2021.
2007 – 2010 Duramax LMM
Credit: motortrend.com
The Diesel Particulate Filter (DPF) was first introduced in the 2007 LMM Duramax engine.
The engine has a 6-speed Allison transmission and features the same compression ratio as its predecessor.
It comes with a V-8 configuration housed in a cast grey iron block and cast aluminum head.
The engine produces 365 horsepower at 3,200 rpm and a torque of 660 lb-ft at 1,600 rpm.
LMMs in vans have 250 hp at 3,200 rpm and 460 lb-ft in torque at 1,600.
The production of LMM brought about new engine control software and increased-capacity cooling systems.
Applications
LMM engines were used in the 2007 Chevrolet Silverado 2500 HD, 3500 HD, 2007 GMC Sierra 2500 HD, 3500 HD, 2007 Chevrolet Express 2500, 3500, and 4500, as well as 2007 GMC Savana 2500, 3500, and 4500.
Common problems
The first common issue in LMM 6.6L engines is the new DPF system and active regeneration that continually malfunctions.
Other issues are:
- Leaking transmission lines;
- Fueling/low fuel pressure;
- Piston and crankshaft failure;
- Allison 1000 power limitations.
Is It Good Or Bad? Should I Buy It?
The introduction of the DPF system makes the LMM a compelling buy.
However, it would help if you did not buy this year’s models due to the improvements and upgrades in the later models from 2011, like the LML.
2011 – 2016 Duramax LML
Credit: dieselworldmag.com
The Duramax LML engines are also 6.6L V-8 engines with turbochargers and intercooler aspirations.
These engines were made alongside the LGH and could produce 397 hp at 3,000 with a torque of 765 lb-ft at 1,600 rpm.
Applications
The V-8 engines were not used in many vehicles like most Duramax engines.
LML was only put in the 2011-2016 Chevrolet Silverado 2500 HD, 3500 HD, and 2011-2016 GMC Sierra 2500 HD and 3500 HD.
Common problems
The recurrent issues of LML engines include;
- DEF pump failure;
- DEF heater problems;
- CP4.2 injection pump failure and NOx sensor failure.
Is It Good Or Bad? Should I Buy It?
LML is the first great buy among the Duramax engines we will recommend.
Experts and frequent users attest to the reliability and efficiency of these engines due to the lack of previous Duramax engine issues like Allison 1000 power limitations and water pump failures.
2010 – 2017 Duramax LGH
The Duramax LGH came with a 6.6L displacement and was used before 2011 when its official production started.
It can produce from 260 to 335 hp at 3,100 rpm and from 525 to 685 lb-ft at 1,600 rpm (refer to the comparison chart for more details).
It also came with DPF and DEF systems to comply with the country’s emissions standards.
Applications
Credit: commons.wikimedia.org
LGH engines were put in vehicles between 2011 and 2016 and 2010 interim Chevrolet Express and GMC Savana vans.
The list of vehicles includes:
- 2011 -2016 Chevrolet Express 2500, 3500, 4500 vans;
- 2011-2016 GMC Savana 2500, 3500, 4500 vans;
- 2011-2012 Chevrolet Silverado 3500 HD chassis cab;
- 2011-2012 GMC Sierra 3500 HD chassis cab.
Common problems
The only common issue with the Duramax LGH is the CP4.2 injection pump failure.
Is It Good Or Bad? Should I Buy It?
LGH engines are good engines considering they have one recurrent issue.
Additionally, introducing DPF and DEF systems is great for us to recommend you buy them.
2017 – 2021 Duramax L5P
Credit: poweredsolutions.gm.com
The Duramax L5P marks the end of the 6.6L V-8 DMAX engines, which produced 445 horsepower at 2,800 rpm and 910 lb-ft torque at 1,600 rpm.
Applications
The L5P is placed in 2017 to current Chevrolet Silverado 2500 HD, 3500 HD, and 2017 to current GMC Sierra 2500 HD and 3500 HD.
Common problems
Oddly enough, the LGH has more recurrent issues than its predecessor. The issues include:
- MAP sensor failure;
- Allison 1000 transmission limitations;
- Fuel injector failure, especially injector number 4.
Is It Good Or Bad? Should I Buy It?
L5P is good, and an excellent buy for your GMC and Chevy needs.
2019 – 2021 Duramax L5D
The Duramax L5D may seem like a different engine, but it is a downgraded version of its predecessor, the L5P.
The purpose was to increase its reliability while at the same time reducing the downtime.
It can produce 350 horsepower at 2,700 rpm and a torque of 700 lb-ft at 1,600 rpm.
Applications
The application includes the 2019 to current Chevrolet Silverado 4500 HD, 5500HD, 6500HD, and 2019 to current international CV series.
Common problems
Duramax L5D is very reliable and efficient, with the only common issue being the air filter failure.
Is It Good Or Bad? Should I Buy It?
Duramax L5D is a great engine and is an excellent buy in the current market.
It has the latest specifications and a broad application base.
2011 – 2021 Duramax XLD25
The Duramax XLD25 is the first non 6.6L engine from DMAX.
This Inline I-4 engine has a 2.5L displacement, making it smaller than any previous Duramax engine.
The engines feature DOHC (double overhead camshaft), four valves per cylinder, and a compression ratio of 16.5:1.
It boasts a horsepower output of 163 at 3,600 rpm and a torque of 280 lb-ft at 2,000 rpm.
Applications
Duramax XLD25 was designed to be used in:
- Chevrolet Colorado S-10;
- Chevrolet Trailblazer for international markets;
- Mid-size pickup trucks;
- SUVs.
Common problems
Vehicle owners have not reported any significant issues with the XLD25 engines.
Is It Good Or Bad? Should I Buy It?
Duramax XLD25 engines are relatively new ones with minor recurrent issues.
They are worth a buy due to their extensive features and durability.
2012 – 2021 Duramax XLD28
The Duramax XLD28 is similar to the XLD25.
However, they produce more power than their predecessor, with a power output of 200 hp at 3,600 rpm compared to the 163 hp at 3,600 rpm of the XLD25. The torque is 360 lb-ft at 2,000 rpm.
The bore and stroke also vary from 3.62 by 3.7 inches in the XLD25 to 3.7 by 3.9 inches in the XLD28.
Applications
You can find Duramax XLD28 in:
- 2012 to current Chevrolet Colorado;
- 2012 to current GMC Canyon;
- 2012 to current Chevrolet Express;
- 2012 to current GMC Savana vans.
Common problems
Like XLD25 engines, the XLD28s have minor issues that may cause concern in terms of their durability and efficiency.
Is It Good Or Bad? Should I Buy It?
You should buy the XLD28 engines if you want a reliable and efficient engine for your Chevy or GMC vehicle.
2014 – 2021 Duramax LWN
The Duramax LWN engines use the same 2.8L displacement as the XLD28 and have a similar inline configuration with four cylinders.
The compression ratio is 16.5: 1 with a power output of 181 hp at 3,400 rpm and 369 lb-ft torque at 2,000 rpm.
Applications
Duramax LWN can be found in:
- 2016 to current Chevrolet Colorado;
- 2016 to current GMC Canyon;
- 2017 to current Chevrolet Express 2500, 3500;
- 2017 to current GMC Savana 2500, 3500.
Common problems
Like most current Duramax engines, the LWNs are relatively new and haven’t been thoroughly tested to figure out their everyday issues. The only reported problems include DEF pump failures with the heater and turbo malfunctions.
Apart from that, the engines are highly reliable.
Is It Good Or Bad? Should I Buy It?
LWN engines are good and a great buy in the current Duramax line-up.
There are no major issues, and the typical issues are easily fixable.
2019 – 2021 Duramax LM2
Credit: dieselresource.com
The Duramax LM2 is the latest addition to the Duramax engine line-up with its 3.0L displacement and unique inline I-6 layout.
The horsepower output is 277 at 3,750 rpm, the torque is 460 lb-ft at 1,500 rpm.
Applications
You may find Duramax LM2 in:
- 2020 to current Chevrolet Silverado 1500;
- 2020 to current GMC Sierra 1500;
- 2021 to current Cadillac Escalade;
- 2021 to current Chevrolet Tahoe;
- 2021 to current Chevrolet Suburban;
- 2021 to current GMC Yukon.
Common problems
Since it’s the newest Duramax model, the issues are not as common as you may detect in older models.
The only problem you may find is weak tie rods, but it is unlikely most of the time.
So far, the LM2 is considered the best 3L inline engine from DMAX.
Is It Good Or Bad? Should I Buy It?
You should buy the LM2 Duramax engine if you are in the market for a newly built 3L engine with DOHC, four valves per cylinder.
Conclusion
The extensive list mentioned above shows the best and the worst model years of the Duramax engines.
You will get the most out of your money with the 2010 – 2017 Duramax LGH, 2011 – 2016 Duramax LML, 2011 – 2021 Duramax XLD25, 2012 – 2021 Duramax XLD28, 2014 – 2021 Duramax LWN, 2017 – 2021 Duramax L5P, and 2019 – 2021 Duramax LM2.
Engines before these are less reliable and plagued with major mechanical and structural issues, as well as missing components.
All in all, the latest Duramax engines are powerful and well-tuned to fit your GM and Chevy needs.
Read more: LBZ Vs. LMM Vs. LML Vs. L5P: Which Engine Is Best For You?
