Chevrolet Silverado / GMC Sierra. Service manual — part 1894

Fig. 46: View Of Tie Strap Through Center Of Actuator
Courtesy of GENERAL MOTORS CORP.

Install tie wrap (1) to retain the reluctor wheel to the sprocket. The reluctor wheel is mounted to
the actuator body with 3 roll pins.

NEW PRODUCT INFORMATION

CAUTION: Refer to Camshaft Position Actuator Removal and Installation

Caution .

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

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

No revisions to the engine specifications.

Torque Values and/or Fastener Tightening Strategies

Connecting rod bolt torques have been increased. Refer to Fastener Tightening Specifications.

New Sealants and/or Adhesives

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

Disassembly and Assembly Procedure Revisions

No disassembly or assembly procedure revisions.

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

No new special tools are required.

A Component Comparison from the Previous Year

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

No new engines/RPOs have been added.

LUBRICATION DESCRIPTION (RPO LY2)

Fig. 47: Lubrication Description (RPO LY2)
Courtesy of GENERAL MOTORS CORP.

Callout

Component Name

200

Camshaft

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Engine lubrication is supplied by a gerotor type oil pump assembly. The oil pump is mounted on
the front of the engine block and driven directly by the crankshaft sprocket. The pump gears
rotate and draw oil from the oil pan sump through a pick-up screen and pipe. The oil is
pressurized as it passes through the pump and is sent through the engine block lower oil gallery.
Contained within the oil pump assembly is a pressure relief valve that maintains oil pressure
within a specified range.

Pressurized oil is directed through the engine block lower oil gallery to the full flow oil filter
where harmful contaminants are removed. A bypass valve is incorporated into the oil filter, which
permits oil flow in the event the filter becomes restricted. A second valve, the oil pressure relief
valve is incorporated into the oil pan. The oil pressure relief valve limits oil pressure directed to
the upper oil galleries and oil manifold assembly to 379-517 kPa (55-75 psi) maximum. When
main oil pressure exceeds 379 kPa (55 psi), the oil pressure relief valve exhausts excess oil to the
sump.

Oil is then directed from the filter to the upper main oil galleries. Oil from the left upper oil
gallery is directed to the crankshaft and camshaft bearings. Oil that has entered both the upper
main oil galleries also pressurizes the valve lifter assemblies and is then pumped through the
pushrods to lubricate the valve rocker arms and valve stems. Oil returning to the pan is directed
by the crankshaft oil deflector. The oil pressure sensor is located at the top rear of the engine.

LUBRICATION DESCRIPTION (RPO LH6/LMG/LY5/LC9)

205

Camshaft Sprocket

209

Valve Lifter - Non-Active Fuel Management

407

Oil Pump Screen

413

Oil Pump

437

Oil Filter

455

Oil Pressure Relief Valve

555

Valley Cover

706

Oil Pressure Sensor

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado