Chevrolet Silverado / GMC Sierra. Service manual — part 2151

Fig. 128: Removing/Installing Intake Manifold Bolts
Courtesy of GENERAL MOTORS CORP.

2. Remove the manifold absolute pressure (MAP) sensor (714). Refer to Intake Manifold

Removal (RPO LY2/LY6/L92) or Intake Manifold Removal (RPO
LH6/LMG/LY5/LC9/L76) .

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

3. Remove the evaporative emission (EVAP) canister purge solenoid valve, EVAP tubes, and

fuel rail with injectors. Refer to Fuel Rail and Injectors Removal .

4. Remove the throttle body and gasket. Refer to Throttle Body Removal .

5. Clean the intake manifold (500) in solvent.

6. Dry the intake manifold with compressed air.

Inspection Procedure

1. Inspect the manifold for the following conditions:

Damaged gasket or sealing surfaces

Loose threaded inserts or studs

Debris or restrictions within the passages of the manifold

Damaged or broken vacuum fittings

Inspect the composite intake manifold assembly for cracks or other damage.

CAUTION: Refer to Safety Glasses and Compressed Air 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

Fig. 129: Inspecting Intake Manifold Cylinder Head Deck For Warpage
Courtesy of GENERAL MOTORS CORP.

2. Inspect the intake manifold cylinder head deck for warpage.

1. Locate a straight edge across the intake manifold cylinder head deck surface.

Position the straight edge across a minimum of two runner port openings.

2. Insert a feeler gage between the intake manifold and the straight edge.

An intake manifold with warpage in excess of 3 mm (0.118 in) over a 200 mm (7.87

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

in) area is warped and should be replaced.

EXHAUST MANIFOLD CLEANING AND INSPECTION

Fig. 130: Exhaust Manifold
Courtesy of GENERAL MOTORS CORP.

IMPORTANT: Do not use the exhaust manifold-to-cylinder head gaskets

again. Upon installation of the exhaust manifold, install a
NEW gasket. An improperly installed gasket or leaking
exhaust system may affect on-board diagnostics (OBD) II
system performance.

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