Chevrolet Silverado / GMC Sierra. Service manual — part 254

Fig. 67: View Of Knock Sensor Wire Harness
Courtesy of GENERAL MOTORS CORP.

1. Remove the intake manifold. Refer to Intake Manifold Replacement.

2. Gently pry up the rubber covers.

3. Disconnect the knock sensor electrical connectors.

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

Fig. 68: View Of Knock Sensors
Courtesy of GENERAL MOTORS CORP.

4. Remove the knock sensors.

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

Fig. 69: View Of Engine Valley Cover, Gasket & Bolts
Courtesy of GENERAL MOTORS CORP.

5. Remove the engine valley cover bolts.

6. Remove the engine valley cover and gasket.

7. Discard the old gasket.

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

Fig. 70: View Of Knock Sensor Oil Seals & Cover
Courtesy of GENERAL MOTORS CORP.

8. Remove the knock sensor oil seals (1) from the cover (2).

9. Clean and inspect the engine valley cover. Refer to Engine Block Valley Cover Cleaning

and Inspection.

Installation Procedure

IMPORTANT: All gasket surfaces should be free of oil or other foreign material

during assembly.

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2