Manufacturer DMAX | Production 2001 - present; | |
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Predecessor 6.2 and 6.5 L Detroit Diesel | ||
The Duramax is a General Motors diesel engine family for trucks, designed by GM and Isuzu. The 6.6-liter Duramax is produced by DMAX, a joint venture between GM and Isuzu in Moraine, Ohio. The Duramax block and heads are poured at The Defiance GM Powertrain foundry in Defiance, Ohio. This engine was initially installed in 2001 model year Chevy and GMC trucks and has been an option since then in pickups, vans, and medium-duty trucks. In 2006, production at Moraine was reportedly limited to approximately 200,000 engines per year. On May 9, 2007, DMAX announced the production of the 1,000,000th Duramax V-8 diesel at its Moraine facility.
Contents
LB7
RPO LB7 (engine code "1") was first introduced in 2001 and continued until early-2004. It is a 32-valve design with high-pressure common-rail direct injection and an experimental composite design cylinder head. The most common issue with the LB7 is injector failure, so common that a special policy bulletin was issued (#04039B). Fuel leaked and entered the crankcase, causing oil dilution. Early on, customers came forward complaining of severe overheating, and in some situations, blown head gaskets. Initially GM denied it was a problem, but after being sued by a consumer group, GM relented and included overheating and blown head gaskets as a warranted item. GM issued a warranty for this after the fact for injectors, which now have 7 year/200,000 mile coverage. The following trucks use the LB7:
Specifications
500 lb-ft @ 1,600 rpm 2004 LB7: 300 hp @ 3,100 rpm LLY: 310 hp @ 3,000 rpm LB7: 520 lb-ft @ 1,800 rpm LLY: 520 lb-ft @ 1,600 rpm The LLY was introduced in 2004 and replaced the LB7 completely mid-year
LLY
The LLY (internally called the 8GF1) (engine code "2") is a 6,599 cc (402.7 cu in) turbocharged engine which debuted in mid-2004 and continued until the end of 2005. It is a 32-valve design with high-pressure common-rail direct injection and aluminum cylinder heads. The LLY was GM's first attempt to implement emissions requirements on their diesel trucks. To meet this goal they turned to a newly developed Garrett turbocharger with a variable geometry vane system and they installed an Exhaust Gas Recirculation valve or (EGR Valve). Learning from problems with injectors in the previous LB7 GM changed the valve covers to allow access to the injectors without having to remove the valve covers, saving significant labor costs if injector replacement became necessary.
The following trucks used the LLY engine:
Specifications
LLY/LBZ
There are two VIN codes for the LBZ. The first is VIN 2. While it is the LBZ it has LLY tune tables.
Second is VIN D. This was introduced in late 2005 and continued into 2007 sold only in the "classic" body style. It has an improved engine computer tune that produces increased power and torque over the 2005.5 LLY version of the motor. First appearance of the Duramax in the Express/Savanna vans.
Changes include:
LBZ applications:
LLY applications:
Specifications
LMM
The LMM (engine code "6") debuted part way through 2007 and ended production with the start of the 2011 calendar year and is mated to the 6-speed Allison transmission. The LMM was the only Duramax offered for model years 2008-2010.
A version was used in Trident Iceni .
Specifications
Emission controls:
Applications:
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. Some mechanical aspects of the engine, such as piston oil flow design for improved temperature control and oil pump design, were also improved to enhance durability even further.
The LML engine was significantly updated for 2011 to provide improved exhaust emissions that comply with the new federal emission standards for diesel engines, provide better engine rigidity and further noise reduction. New 29,000 PSI piezo injectors, a complete fuel system-hardening to tolerate up to 20% biodiesel mixtures and urea injection (to reduce nitrogen oxides) with a 5.3 gallon urea tank are updating the fuel and emissions systems. This engine has a fuel injector in the exhaust tract, to allow raw fuel injection during the particulate filter recycling routine. The RPO LML engine is rated at 397 horsepower (296 kW) at 3000 rpm and 765 lb·ft (1,037 N·m) of torque at 1600 rpm.
L5P
The L5P duramax is the latest version of the Duramax V8 diesel engine. Introduced in the 2017 model year it is the most powerful diesel engine GM has produced with 445 hp @ 2,800 rpm and 910 lb-ft @ 1,600 rpm. Design spec performance can excede 550 bhp @ 3050 rpm and 1050 lb-ft at 1975 rpm.
LGH
The 6.6L Duramax diesel engine (VIN code "L") is used on 2010 interim and 2011 Chevrolet Express and GMC Savana vans and 2011 Chevrolet Silverado and GMC Sierra trucks with RPO ZW9 (chassis cabs or trucks with pickup box delete). The LGH engine is rated at 335 bhp (250 kW) at 3100 rpm and 685 lb·ft (929 N·m) at 1600 rpm. Similar to the LML this engine also uses a DPF and DEF system to meet emission standards.
LMK
This engine is not yet commercially launched although it was touted in the automobile press as one of the most important new engine concepts for small trucks and SUVs by finally delivering a capable diesel engine in a compact enough package. The engine project is currently on indefinite hold by GM. General Motors planned a 4.5-litre 72-degree V8 for light-duty applications which would be built at GM's powertrain facility in Tonawanda, New York after 2009. Designed to fit in the same space as a Chevrolet Small-Block engine, it is expected to produce over 310 bhp (230 kW) and 520 lb·ft (705 N·m) of torque. It added urea injection, 29,000-psi (2,000 bar) piezo-electric common-rail fuel system over previous Duramax architecture.
It was initially targeted for the Chevy Silverado/GMC Sierra and Hummer H2. Unlike previous Duramax engines, the 4.5-liter is planned to be designed and built entirely by GM, without assistance from Isuzu.
As of March 2009, a GM spokesperson stated the engine project has been put on an "indefinite hold" due to current economic conditions.