GM Service Manual Online
For 1990-2009 cars only

The purpose of New Product Information is to highlight or indicate important product changes from the previous model year.

Changes may include one or more of the following items:

    • Torque values and/or fastener tightening strategies
    • Changed engine specifications
    • New sealants and/or adhesives
    • Disassembly and assembly procedure revisions
    • Engine mechanical diagnostic procedure revisions
    • New special tools required
    • A component comparison from the previous year

Torque Values and/or Fastener Tightening Strategies

    • All fasteners and threaded holes on the 4.8, 5.3, and 6.0 liter engines utilize metric threads.
    • Cylinder head, connecting rod, crankshaft balancer, and main bearing cap bolts now apply a torque angle strategy.
    • Certain fasteners should not be reused. Bolts, studs, or other fasteners that must be replaced will be called out in the specific service procedure.
    • A second design connecting rod bolt may be used. The proper fastener tightening value must be used with the correct bolt.
    • Refer to Piston, Connecting Rod, and Bearing Installation .
    • Refer to Fastener Tightening Specifications and Thread Repair Specifications .

Changed Engine Specifications

    • The internal components for the 4.8, 5.3, and 6.0 liter engines are of a new design and have specific tolerances and clearances for each component.
    • Cylinder boring and honing is permitted on the 2000 engine block.
        A 0.50 mm (0.02 in) oversize piston and piston ring set are available for service.
    • Refer to Engine Mechanical Specifications .

New Sealants and/or Adhesives

    • Threadlocking material is used on the fuel rail, ignition coil bracket bolts, intake manifold, cylinder head M8/M11, flywheel, and exhaust manifold bolt threads.
    • A pipe sealant type material is used on the engine block coolant and oil gallery plugs, oil pressure sensor threads, and engine block oil pan surface.
    • A sealant type material is used on the flange of the M8 crankshaft bearing cap side bolts.
    • Refer to Sealers, Adhesives, and Lubricants .

Disassembly and Assembly Procedure Revisions

    • The 4.8, 5.3, and 6.0 liter engine front and rear covers are adjustable and must be aligned properly with the oil pan surface and crankshaft assembly.
    • The 4.8, 5.3, and 6.0 liter engine oil pans are a structural member of the powertrain and must be aligned properly with the rear of the engine block and transmission bellhousing.
    • Crankshaft balancer installation has a specific procedure to ensure complete installation.
    • Early design water pumps will have a bolt-on drive belt pulley. Later design water pumps will have a non-removeable press-on drive belt pulley.
    • The piston, pin, and connecting rod are to be serviced as an assembly.
    • Newer design pistons have a graphite coated piston skirt. The coated skirt outside diameter (OD) may be slightly larger than the cylinder bore inside diameter (ID) and the piston assembly may have a slight interference fit to the cylinder bore during initial installation.

Engine Mechanical Diagnostic Procedure Revisions

Base Engine Misfire, Valve Train, and other diagnostic information is now provided in table form. Potential or probable causes are supplied for each specific concern.

New Special Tools Required

    • A variety of new tools have been developed to assist in engine disassembly, assembly, and on-vehicle service.
    • Refer to Special Tools .

A Component Comparison from the Previous Year

    • All water pumps will have a press on non-serviceable accessory drive belt pulley.
    • Certain 6.0L applications will have a drive-by-wire throttle body system.
    • The vapor vent pipe located above the engine valley cover will now be referred to as the engine coolant air bleed pipe. Refer to Disassembled Views .