GM CHEVROLET GMC DURAMAX DIESEL ENGINE SERVICE
Duramax 6.6L V8 Diesel Pickup Truck Engine Problems, Solutions, Repair, Rebuild, Overhaul & Maintenance Service
Cummins Automotive & Diesel Service will tune up, repair, performance enhance, rebuild, overhaul and maintain your Chevrolet or General Motors GMC Duramax diesel truck engine. We will service your Duramax engine in our Sherwood, Oregon shop or at your location via our mobile roadside repair service. Look no further for professional, ethical, expert technicians to repair your Chevrolet Duramax diesel engine, whether it be a Silverado HD Heavy Duty truck, Kodiak Medium Duty truck, Express Cargo van or a GMC HD Heavy Duty Sierra Denali truck, Topkick Medium Duty truck, Savana Cargo or Cutaway van. We are your solution for higher standards in Duramax engine service, maintenance and repair. We have an outstanding team of technicians who surpass the competition. Cummins Automotive & Diesel Service will service your Chevrolet or GMC Duramax new or rebuilt 6.6 Liter engines with precision and cost efficiency.
Duramax Engines Serviced By Cummins Automotive & Diesel Service
Duramax 6.6 Liter LB7 V-8 Turbo Diesel Engine – 403 cu. in.
Cummins Automotive & Diesel Service will tune up, repair, performance enhance, rebuild, overhaul and maintain your Duramax LB7 diesel engine. The Duramax GM turbo diesel engine identified with the Regular Production Option, RPO, Code of LB7 was produced from 2001 to 2004 and was installed in the Chevrolet Silverado HD and the GMC Sierra HD. Compared to newer diesel engines, the Duramax LB7 is known for its reliability and simplicity.
The Duramax LB7 diesel engine was a first-in-class engine with the common rail direct fuel injection. Unfortunately, it consistently suffered injector failures. The failure rate was common enough that a GM recall was necessary for replacement of the original injectors. If your Duramax LB7 diesel engine has this problem, Cummins Automotive & Diesel Service can replace your original injectors and with the replacement injectors, and with the recall replacement, you get a GM extended warranty of up to 200,000 for the new components.
Evidence, as reports seem to indicate, showed that poorly filtered fuel is one of the leading causes of the original injector failure. Aftermarket manufacturers have produced components to fix the poor fuel filtering problem. If you have not had the fuel filter components of your Duramax LB7 diesel engine upgraded, Cummins Automotive & Diesel Service can service your engine to correct this problem.
A characteristic of the Duramax LB7 diesel engine, that some diesel engine enthusiasts particularly like about it, is its simplicity. The Duramax LB7’s simplicity stems from its being introduced, built and produced before stringent diesel emissions regulations were imposed, so owners do not have to concern themselves with the issues some of the newer diesel engine models have with Diesel Exhaust Fluid (DEF), Diesel Particulate Filters (DPF), and Selective Catalytic Reduction (SCR) difficulties.
Duramax 6.6 Liter LLY V-8 Turbo Diesel Engine – 403 cu. in.
Cummins Automotive & Diesel Service will tune up, repair, performance enhance, rebuild, overhaul and maintain your Duramax LLY diesel engine. The Duramax GM turbo diesel engine identified with the Regular Production Option, RPO, Code of LLY was introduced during the 2004 model year as a replacement to the LB7 Duramax V8. It was installed in Chevrolet Silverado Heavy Duty pickup trucks and GMC Sierra Heavy Duty pickup trucks in 2004, 2005 and 2006.
When the Duramax LLY V8 diesel truck engine debuted in 2004, it had an SAE-certified output rating of 310 horsepower and 520 pound-feet of torque. The 2006 model year boasted a significant torque boost of 605 pound-feet of torque. The beefy torque benefited from variable-valve timing which enabled the torque to be delivered as early as 1,600 RPMs, revolutions per minute.
Gone was the LB7’s simplicity with the introduction of the LLY in that the LLY was fitted with emissions controlling technology. The emissions technology resulted in more issues and drawbacks related to the mandatory addition of more moving parts, but it also had the advantages of improved drivability and a turbocharger that spooled more quickly. The improved spool time compounded into two additional benefits of providing earlier torque delivery and less particulate pollutants.
With the Duramax LLY diesel engine, General Motors avoided the fuel injector woes of the LB7, but the LLY was prone to overheating. The Duramax LLY diesel engine overheating issues are more severe when the trucks are used for towing, which gives rise to speculation that the problem is related to restrictive air flow components and/or the improper maintenance of cooling components. If you own a diesel truck with the Duramax LLY diesel engine, Cummins Automotive & Diesel Service can service your truck to help ensure you avoid the potential overheating associated with the engine.
Duramax 6.6 Liter LBZ V-8 Turbo Diesel Engine – 403 cu. in.
Cummins Automotive & Diesel Service will tune up, repair, performance enhance, rebuild, overhaul and maintain your Duramax LBZ diesel engine. The Duramax GM turbo diesel engine identified with the Regular Production Option, RPO, Code of LBZ was introduced midway through the 2006 model year, when it replaced the 6.6 liter LLY Duramax. The Duramax LBZ diesel engine was installed in Chevrolet Silverado Heavy Duty pickup trucks and GMC Sierra Heavy Duty pickup trucks in 2006 and 2007. Horsepower increased to 360 and torque increased to 650 pound-feet of torque. Diesel engine enthusiasts flock to the Duramax LBZ V8 diesel engine due to improvements over its predecessors and its relative simplicity compared to other, newer, emissions controlled diesel engines.
The Duramax LBZ V8’s SAE-certified output of 360 horsepower and 650 pound-feet of torque (an increase of 50 horsepower and 45 pounds of torque more than the LLY Duramax) was made possible by revisions in technology and the introduction of new technology. The revised and new technologies delivered a Duramax LBZ diesel engine with a more rigid engine block, with significantly stronger connecting rods, with revised fuel injectors that increased the injection system’s maximum pressure from 23,000 psi to 26,000 psi, and with a larger inlet manifold for the turbocharger.
The Duramax LBZ diesel truck engine had fewer emissions controls than later models and even though it did have Exhaust Gas Recirculation (EGR) and Diesel Oxidation Catalyst (DOC) components, they seemed to not decrease performance and fuel economy as much as the emissions components of later models.
If you own a truck with the Duramax LBZ diesel engine, your engine’s weak point is the cast aluminum pistons where aluminum bits are prone to cracking, especially when the engine’s output is boosted. Additionally, the use of wrist pin bushings can be a cause of failure as well. Cummins Automotive & Diesel Service can troubleshoot, run diagnostics, and look at your pistons to see if work can be done that can save you major repair costs down the road. Cummins Automotive can also determine if your engine’s output was boosted and inspect your bushings to determine if wrist pin bushings have been installed and service your engine to set the output boost optimally or to replace bushings with optimal equipment.
Duramax 6.6 Liter LMM V-8 Turbo Diesel Engine – 403 cu. in.
Cummins Automotive & Diesel Service will tune up, repair, performance enhance, rebuild, overhaul and maintain your Duramax LMM diesel engine. The Duramax GM turbo diesel engine identified with the Regular Production Option, RPO, Code of LMM was introduced midway through the 2007 model year, when it replaced the 6.6 liter LBZ Duramax diesel engine. The Duramax LMM diesel engine was installed in Chevrolet Silverado Heavy Duty pickup trucks and GMC Sierra Heavy Duty pickup trucks from 2007 to 2010. The Duramax LMM diesel engine had an SAE-certified rating of 365 horsepower and 660 pound-feet of torque. GM succeeded in improving the Duramax V8’s performance despite the onset of more restrictive emissions regulations.
In the wake of government imposed emissions controls, GM continued to innovate with technologies and design to refine the Duramax 6.6L LMM V8 diesel engine. General Motors added an intake airflow valve to regulate Exhaust Gas Temperatures (EGTs) and they revised the head configuration for a more efficient and effective passage of coolant through its water jackets.
The legislative emissions control specification, which required nitrogen oxide (NOx) emissions be reduced by 50 percent, required an increase in exhaust gas recirculation (EGR) and the addition of a new filter, the Diesel Particulate Filter (DPF). The addition of the EGR system and the DPF increased the Duramax LMM’s overall heat production, making the ability to reduce heat an important and necessary countermeasure. To compensate for the extra heat, a larger EGR cooler was adapted to the LMM Duramax V8.
GM also tinkered with the Duramax LMM fuel injectors. Instead of sticking with the 7-hole, 158-degree injector nozzles that the Duramax LBZ diesel engine utilized, the LMM went back to the 6-hole, 159-degree injector nozzles. After the Duramax LMM diesel engine’s innovative technologies and design refinements were complete, the power plant exhibited the same piston vulnerabilities that the Duramax LBZ became known for; pistons prone to cracking under heavy load. If you own a truck with the GM Duramax LMM diesel engine, Cummins Automotive & Diesel Service can troubleshoot, run diagnostics, and look at your pistons to see if service or maintenance work can be done that may save you future repair costs.
Duramax 6.6 Liter LGH V-8 Turbo Diesel Engine – 403 cu. in.
Cummins Automotive & Diesel Service will tune up, repair, performance enhance, rebuild, overhaul and maintain your Duramax LGH diesel engine. The Duramax GM turbo diesel engine identified with the Regular Production Option, RPO, Code of LGH is an engine produced by General Motors for full size, heavy duty, HD vans. Displacing 6.6 liters in a V8 configuration, the LGH is part of the Duramax engine family of turbo diesel engines originally created in partnership with Isuzu. It is mechanically similar to the 6.6 liter LML Duramax engine, but it has a lower power rating. The Duramax LGH diesel engine was installed in 2010 to 2016 Chevrolet Silverado HD pickup trucks, GMC Sierra HD pickup trucks, Chevrolet Express vans and GMC Savana vans.
By the time the Duramax 6.6L LGH turbo diesel heavy duty truck engine rolled around, GM had established itself with the reputation as the manufacturer of a strong, powerful, and efficient, diesel engine. The LGH’s further innovation only added to this sterling reputation.
The Duramax LGH’s common-rail direct injection fuel system of the 2000-Bar Fuel System with Piezo injectors allowed for a more precise metering of the fuel, smoother idle, and lower combustion noise. Its variable-vane, variable-geometry turbocharger with self-adjusting turbine vanes and electronic controlled, automatically adjusted boost pressure and exhaust backpressure, allowed the engine to deliver more power with lower exhaust emissions and no decrease in overall fuel efficiency. The Duramax LGH diesel engine successfully reduced NOx emissions by 63 percent and it is capable of running on B20 biodiesel, a fuel composed of 20 percent biodiesel and 80 percent conventional diesel.
The Duramax LGH diesel engine’s refinement in metals, namely the cylinder block, cylinder walls, lower crankcase, crankshaft, connecting rods, pistons, and head, were refinements worth their weight in gold. For smoother and quieter engine operation, the cylinder block incorporated enhanced casting with strong and durable cast iron, induction-hardened cylinder walls and five nodular iron main bearings. The die-cast aluminum lower crankcase strengthened the engine block and reduced the engine’s overall weight. Inside the cylinder block was a robust rotating assembly that featured a forged steel crankshaft, forged steel connecting rods and forged aluminum pistons. The crankshaft was surface-hardened by nitriding, the most effective means of limiting wear and ensuring durability.
GM redesigned the pistons in the Duramax LGH diesel engine by ditching the pin bushings to reduce reciprocating weight and improve throttle response. The pistons were strengthened and the piston connecting rods featured a smaller diameter pin bore on the small end to support the strengthened pistons. Oil jets were located at the bottom of the cylinder bores and engine oil was sprayed on the bottom of the pistons. The extra lubrication cooled the pistons and reduced friction.
The Duramax LGH diesel engine featured an aluminum head designed with six head bolts per cylinder and four valves per cylinder. The aluminum material of the head reduced the engine’s overall weight and the six-bolt design provided the necessary head-clamping strength needed for high-compression, turbocharged applications.
Duramax 6.6 Liter LML V-8 Turbo Diesel Engine – 403 cu. in.
Cummins Automotive & Diesel Service will tune up, repair, performance enhance, rebuild, overhaul and maintain your Duramax LML diesel engine. The Duramax GM turbo diesel engine identified with the Regular Production Option, RPO, Code of LML is an engine that was produced by General Motors for full size, heavy duty, HD pickup trucks. The Duramax LML diesel engine is nearly identical to the LGH and it displaces 6.6 liters in a V8 configuration and it is a popular engine in the Duramax family of heavy duty engines in the heavily emissions controlled category of diesel engines. The Duramax LML diesel engine was installed in 2010 to 2016 Chevrolet Silverado HD pickup trucks and GMC Sierra HD pickup trucks.
The Duramax LML diesel engine is known as the first Duramax V8 to feature a “9th injector” fuel system configuration. The accommodation was made to provide fuel during the DPF regeneration process. The Duramax LML’s common-rail direct injection fuel system of the 2000-Bar Fuel System with Piezo injectors allowed for a more precise metering of the fuel, smoother idle, and lower combustion noise. Its variable-vane, variable-geometry turbocharger with self-adjusting turbine vanes and electronic controlled, automatically adjusted boost pressure and exhaust backpressure, allowed the engine to deliver more power with lower exhaust emissions and no decrease in overall fuel efficiency. The Duramax LML diesel engine successfully reduced NOx emissions by 63 percent and it is capable of running on B20 biodiesel, a fuel composed of 20 percent biodiesel and 80 percent conventional diesel.
The Duramax LML diesel engine’s refinement in metals, namely the cylinder block, cylinder walls, lower crankcase, crankshaft, connecting rods, pistons, and head, were refinements worth their weight in gold. For smoother and quieter engine operation, the cylinder block incorporated enhanced casting with strong and durable cast iron, induction-hardened cylinder walls and five nodular iron main bearings. The die-cast aluminum lower crankcase strengthened the engine block and reduced the engine’s overall weight. Inside the cylinder block was a robust rotating assembly that featured a forged steel crankshaft, forged steel connecting rods and forged aluminum pistons. The crankshaft was surface-hardened by nitriding, the most effective means of limiting wear and ensuring durability.
GM redesigned the pistons in the Duramax LML diesel engine by doing away with the pin bushings to reduce reciprocating weight and improve throttle response. The pistons were strengthened and the piston connecting rods featured a smaller diameter pin bore on the small end to support the strengthened pistons. Oil jets were located at the bottom of the cylinder bores and engine oil was sprayed on the bottom of the pistons. The extra lubrication cooled the pistons and reduced friction.
The Duramax LML diesel engine featured an aluminum head designed with six head bolts per cylinder and four valves per cylinder. The aluminum material of the head reduced the engine’s overall weight and the six-bolt design provided the necessary head-clamping strength needed for high-compression, turbocharged applications.
The Duramax LML diesel engine is known to have CP4.2 injection pump failures. The failure can happen suddenly, without warning and the repair bill can approach $10K, so it can pay to prevent it from happening with regular fuel filter changes, use of quality diesel fuel and the installation of a CP3 retrofit kit. Cummins Automotive & Diesel Service can look at your Duramax LML diesel engine and guide you on your best action to avoid injection pump failure. Another issue with the Duramax LML diesel engine can be a Diesel Exhaust Fluid (DEF) pump failure. Contaminated or dirty exhaust fluid may be a contributing factor to DEF pump failures. A failed DEF pump will not damage the diesel engine, but it will trigger the DEF warning light and the truck’s drivability can be affected 200 miles thereafter or following the next fuel fill up. Cummins Automotive & Diesel Service can look at your Duramax LML diesel engine and your DEF pump and guide you on your best action to potentially avoid failure later on.
Duramax 6.6 Liter L5P V-8 Turbo Diesel Engine – 403 cu. in.
Cummins Automotive & Diesel Service will tune up, repair, performance enhance, rebuild, overhaul and maintain your Duramax L5P diesel engine. The Duramax GM turbo diesel engine identified with the Regular Production Option, RPO, Code of LP5 is a turbo diesel engine produced by General Motors for use in full size, heavy duty, HD pickup trucks. The Duramax L5P diesel engine displaces 6.6 liters in a V-8 configuration and as it replaces the Duramax V8 LML diesel engine, it represents the new generation of Duramax engines. The Duramax LP5 diesel engine debuted in 2017 with the Chevrolet Silverado HD and the GMC Sierra HD and continued to be used into 2021 and beyond.
The Duramax L5P diesel engine produced an SAE certified 445 horsepower (332 kW) and 910 pound-feet of torque (1,234 Nm). The Duramax 6.6L L5P engine provides 90 percent of peak torque at a low 1,550 rpm and sustains it through 2,850 rpm, for strong pulling power at low speeds. The L5P also features a new camshaft profile and improved cylinder head design. Its new electronically controlled, variable-vane turbocharger allows the engine to produce more power with lower exhaust emissions. The engine’s advanced variable-vane mechanism allows greater exhaust temperature capability, enabling the engine to achieve higher power at lower cylinder pressure.
The Duramax L5P diesel engine’s newly designed air intake system, with its functional hood scoop, drives cool and dry air into the engine for sustained performance and cooler engine temperatures during difficult, steep grade towing. Cooler air helps the engine run better under load in conditions where engine and transmission temperatures can rise quickly. This enables the Duramax to maintain more power and vehicle speed when towing in the toughest conditions.