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 1 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

Changed engine Specifications

A variety of specifications have been revised based on the new design LY6 engine. Refer to Engine Mechanical Specifications .

Torque Values and/or Fastener Tightening Strategies

    • All fasteners and threaded holes on the LY6 engine utilize metric threads.
    • Cylinder head, connecting rod, crankshaft balancer, and main bearing cap bolts now apply a torque angle tightening strategy.
    • Certain fasteners should not be used again. Bolts, studs, or other fasteners that must be replaced, will be called out in the specific service procedure.
    • The camshaft position actuator is now retained to the front of the camshaft using a single bolt/valve design with a torque and angle tightening strategy. Refer to Fastener Tightening Specifications .

New Sealants and/or Adhesives

Sealers and adhesives, as required, are identified within the specific service procedures. Refer to Adhesives, Fluids, Lubricants, and Sealers .

Disassembly and Assembly Procedure Revisions

A variety of procedures have been revised based on the new design LY6 engine.

Engine Mechanical Diagnostic Procedure Revisions

Diagnosis on a vehicle should follow a logical process. Strategy based diagnostics is a uniform approach for repairing all systems. The diagnostic flow may always be used in order to resolve a system condition. The diagnostic flow is the place to start when repairs are necessary. For a detailed explanation, refer to Diagnostic Starting Point - Engine Mechanical .

New Special Tools Required

Timing belt tensioner retaining pin EN 46330 is used to retain the timing chain tensioner during the installation procedure.

A Component Comparison from the Previous Year

    • The 6.0L LQ4 VIN U Gen 3 engine is replaced by the 6.0L LY6 VIN K Gen 4 engine. Refer to Engine Component Description and Camshaft Position Actuator and Solenoid Valve Description .
    • Second design engines will use a rivet-type plug replacing the coolant air bleed covers located at the top rear of each cylinder head. To properly repair a leaking plug, remove cylinder head from the engine, remove the plug from the cylinder head and install first design coolant air bleed cover and bolt.