thermostat
Tools
These are some common tools used to work on this device. You might not need every tool for every procedure.
Background and Identification
The LB7 Duramax engine is a 6.6-liter engine produced by DMAX, a joint venture between General Motors and Isuzu. The LB7 is part of General Motors’ Duramax V8 engine line. The LB7 was initially installed in 2001 Chevrolet and GMC trucks and was an option in pickups, vans, and medium-duty trucks between 2001 and 2004. The LB7 appeared as the engine to adopt common rail technology (Dodge did not implement its own common rail Cummins engines until 2003 and Ford’s Power Stroke engines were not released until 2008). The LB7 predates emissions regulations, making it unique to other Duramax models. It has been praised for reliability and is considered a particularly economical variation of the engine.
The LB7 is included in the Chevrolet Silverado HD, GMC Sierra HD, GMC TopKick (medium duty), and Chevrolet Kodiak (medium duty) vehicles. The LB7 sometimes has issues with failing fuel injectors. Injector failures became so frequent that General Motors recalled the poorly designed units and replaced them with an updated design. The factory warranty was extended to cover the new injectors for up to 200,000 miles. Despite these issues, the Duramax was featured in Ward’s “10 Best Engines” for 2001 and 2002.
The LB7 was available mated to the Allison 1000 five-speed automatic transmission or the ZF six-speed manual transmission.
Technical Specifications
Engine: 6.6L Duramax LB7, 90-degree V-8 diesel
Years Produced: 2001 - 2004 model years
VIN Code: 1 (8th digit of VIN)
Displacement: 403 cubic inches, 6.6 liters
Assembly Site: DMAX engine plant, Moraine, Ohio
Head/Block Material: Aluminum cylinder heads, cast iron engine block
Compression Ratio: 17.5: 1
Minimum Cylinder Pressure: 300 psi (minimum compression test pressure)
Bore: 4.055" (103 mm)
Stroke: 3.897" (99 mm)
Aspiration: Turbocharged and intercooler; IHI RHG6 wastegate turbocharger, air-to-air intercooler
Injection: Direct injection, Bosch 23,000 psi high-pressure common rail with Bosch CP3 injection pump
Valvetrain: OHV (overhead valve), 4 valves per cylinder (32 valves)
Oil Capacity: 10 quarts w/ filter
Engine Weight: Approx. 835 lbs
Idle Speed: ~ 680 rpm
Max Engine Speed: 3,250 rpm (rev limiter)
Peak Horsepower:
- 235 hp @ 2,700 rpm (2001 model year)
- 300 hp @ 3,100 rpm (2004 model year)
Peak Torque:
- 500 lb-ft @ 1,600 rpm (2001 model year)
- 520 lb-ft @ 1,800 rpm (2004 model year)
Engine Dimensions:
- Length: 30 inches
- Width: 30 inches
- Height: 32 inches