Chevrolet Silverado / GMC Sierra. Service manual — part 367

3. Remove the valve stem keys (225).

4. Remove the valve spring cap (224).

5. Remove the valve spring (223).

6. Remove the valves (228).

7. Remove the valve stem oil seal (222). Refer to Separating Parts.

Fig. 472: Locating Cylinder Head Core Hole Plug
Courtesy of GENERAL MOTORS CORP.

8. Remove the cylinder head core hole plugs (216), as required.

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

Fig. 473: Locating Coolant Temperature Sensor
Courtesy of GENERAL MOTORS CORP.

9. Remove the coolant temperature sensor (725) from the left cylinder head.

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

Fig. 474: Locating Coolant Plug
Courtesy of GENERAL MOTORS CORP.

10. Remove the cylinder head plug (229) from the right cylinder head.

Disassemble

CYLINDER HEAD CLEANING AND INSPECTION

Tools Required

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

J 8089 Carbon Removal Brush. See Special Tools.

J 9666 Valve Spring Tester. See Special Tools.

Cleaning and Inspection

Fig. 475: Cleaning Carbon Using J 8089
Courtesy of GENERAL MOTORS CORP.

CAUTION: Refer to Safety Glasses Caution .

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2