Chevrolet Silverado / GMC Sierra. Service manual — part 2139

Fig. 92: 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 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

J 8089 Carbon Removal Brush. See Special Tools .

J 9666 Valve Spring Tester. See Special Tools .

Inspection

Fig. 93: Removing Carbon From Combustion Chambers
Courtesy of GENERAL MOTORS CORP.

CAUTION: Refer to Safety Glasses 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

1. Clean the following components:

Use the J 8089 in order to remove the carbon from the combustion chambers. See
Special Tools .

Gasket surfaces

Refer to Replacing Engine Gaskets .

Valve stems and heads on a buffing wheel

Bolt hole threads

Remove all dirt, debris, or threadlocking material from the bolt holes.

2. Inspect the cylinder head for the following conditions:

1. Cracks in the exhaust ports and combustion chambers

2. External cracks in the water chambers

3. Gasket surfaces for excessive scratches or gouging

Refer to Replacing Engine Gaskets .

4. Bolt hole threads for debris or damaged threads

Refer to Thread Repair or Thread Repair Specifications .

IMPORTANT:

When cleaning a cylinder head in a thermal type oven,
do not exceed 204°C (400°F).

Be careful not to scuff the chamber.

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. 94: Inspecting Cylinder Head For Warpage
Courtesy of GENERAL MOTORS CORP.

3. Inspect the cylinder head for warpage. Refer to Engine Mechanical Specifications (RPO

LY5 VIN J) or Engine Mechanical Specifications (RPO LC9 VIN 3) or Engine
Mechanical Specifications (RPO LY2 VIN C) or Engine Mechanical Specifications
(RPO LH6 VIN M) or Engine Mechanical Specifications (RPO LMG VIN 0) or
Engine Mechanical Specifications (RPO LY6 VIN K) or Engine Mechanical
Specifications (RPO L76 VIN Y) or Engine Mechanical Specifications (RPO L92
VIN 8) .

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