Duramax V8 engine


The Duramax V8 engine is a General Motors Diesel V8 engine family for trucks. 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 County, Ohio. This engine was initially installed in 2001 Chevrolet 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. The 2,000,000th Duramax V8 engine rolled off the line in Moraine on March 24, 2017.

Engine RPO Codes

LB7

LB7 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. 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.
The following trucks use the LB7:
The LLY was introduced in 2004 and replaced the LB7 completely mid-year

LLY

The LLY is a 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 installed an 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:
There are two VIN codes for the LBZ. The first is VIN 2 produced in late 2005 and early 2006. The VIN 2 engine is mechanically and physically the same as the VIN D engine but utilizes LLY engine tuning due to the LBZ tuning taking longer to be EPA certified and placed into production.
The second is VIN D. This was introduced in 2006 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 LLY version of the engine. First appearance of the Duramax in the Express/Savanna vans. The LBZ is one of the more sought after Duramax engines due to its strength, reliability, and being pre-emissions.
Changes include:
LBZ applications:
LLY applications:
CodeYearsPower outputTorqueRedline
LB7,
GMC Sierra 2500HD / 3500 Classic )		2001–2004
@ 3200 rpm
@ 1600 rpm		3450 rpm
LLY,
GMC TopKick Medium Duty 		2004–2005
@ 3000 rpm
@ 1600 rpm		3200 rpm
LBZ,
GMC TopKick Medium Duty )		2006–2007
@ 3000 rpm
@ 1600 rpm		3200 rpm
LLY 2006–2007
@ 3200 rpm
@ 1600 rpm		3450 rpm

LMM

The LMM 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 2007–2010. A version was used in the Trident Iceni.

Specifications

CodeYearsPower outputTorqueRedline
LML 2011–2016
@ 3000 rpm
@ 1600 rpm		3450 rpm
LMM 2007–2010
@ 3200 rpm
@ 1600 rpm		3450 rpm
LMM,
GMC TopKick Medium Duty )		2007–2010
@ 3000 rpm
@ 1600 rpm		3250 rpm
LMM,
GMC TopKick Medium Duty )		2007–2010
@ 3000 rpm
@ 1600 rpm		3250 rpm
LMM 2007–2010
@ 3200 rpm
@ 1600 rpm		3450 rpm
LMM 2011–2016
@ 3100 rpm
@ 1600 rpm		3450 rpm

Emission controls:
Applications:
The 6.6L Duramax diesel engine is used on 2010 interim and 2011 Chevrolet Express and GMC Savana vans and 2011 Chevrolet Silverado and GMC Sierra trucks with RPO ZW9. The LGH engine is rated at at 3100 rpm and at 1600 rpm. Similar to the LML this engine also uses a DPF and DEF system to meet emission standards.

LML

The 6.6L RPO LML 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 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 at 3000 rpm and 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 pickup truck engine GM has produced with at 2,800 rpm and at 1,600 rpm. Design spec performance can exceed at 3050 rpm and at 1975 rpm.