Chevrolet Silverado / GMC Sierra. Manual - part 581
Fig. 12: View Of Valve Stem Oil Seal & Valve Spring
Courtesy of GENERAL MOTORS CORP.
2. Remove the valve keys (1).
3. Remove the J 8062 from the cylinder head.
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
4. Remove the valve spring upper seat (2).
5. Remove the valve spring (3).
6. Remove the valve (6).
7. Remove the valve stem seal (4) using J 38820 . See Special Tools .
8. Remove the valve spring lower seat (5).
CYLINDER HEAD CLEANING AND INSPECTION
Tools Required
J 9666 Valve Spring Tester
EN-47909 Injector Bore and Sleeve Cleaning Kit
Inspection
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Fig. 13: Measuring Cylinder Head For Warpage
Courtesy of GENERAL MOTORS CORP.
1. Clean the cylinder head of all foreign material. Do not use a motorized wire brush on any
gasket sealing surface.
2. Clean the threaded holes.
3. Clean the injector bores using EN-47909 .
4. Inspect the cylinder head for the following:
Damage to the gasket surfaces
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Damage to the threaded bolt holes
Cracks in the exhaust ports
External cracks in the water chamber
Cracks between the valve seats
Restrictions in the intake or exhaust passages
Restrictions in the cooling system passages
Rusted, damaged or leaking core plugs
5. Measure the cylinder head for warpage with a straight edge and a feeler gauge. A cylinder
head block deck with warpage in excess of 0.075 mm (0.0030 in) within a 516.5 mm (20.33
in) area must be replaced.
Fig. 14: Measuring Cylinder Head Exhaust Manifold Deck For Warpage
Courtesy of GENERAL MOTORS CORP.
6. Measure the cylinder head exhaust manifold deck for warpage. A cylinder head exhaust
manifold deck with warpage in excess of 0.1 mm (0.0039 in) within a 453 mm (17.83 in)
area must be replaced.
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado