Hummer H2. Manual - part 1842

Clean the intake manifold internal passages.

8. Dry the intake manifold with compressed air.

Inspection Procedure

Fig. 536: Throttle Body & Nuts
Courtesy of GENERAL MOTORS CORP.

1. Inspect the throttle body studs and threaded inserts for looseness or damaged threads.

2. Inspect the wire harness stud and threaded insert for looseness or damaged threads.

CAUTION: Refer to Safety Glasses Caution in Cautions and Notices.

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

Fig. 537: Fuel Rail & Injectors
Courtesy of GENERAL MOTORS CORP.

3. Inspect the fuel rail bolt inserts for looseness or damaged threads.

4. Inspect the intake manifold vacuum passages for debris or restrictions.

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

Fig. 538: View Of MAP Sensor
Courtesy of GENERAL MOTORS CORP.

5. Inspect for damaged or broken vacuum fittings, damaged MAP sensor (714) mounting bore, or broken

MAP sensor retaining tabs.

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

Inspect the areas between the intake runners.

7. Inspect all the gasket sealing surfaces for damage.

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

Fig. 539: Inspecting Fuel Injector Bores For Excessive Scoring Or Damage
Courtesy of GENERAL MOTORS CORP.

8. Inspect the fuel injector bores for excessive scoring or damage.

9. 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 gauge between the intake manifold and the straight edge.

A intake manifold with warpage in excess of 3 mm (0.118 in) over a 200 mm (7.87 in) area is
warped and should be replaced.

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2