Chevrolet Silverado / GMC Sierra. Service manual — part 2209

1. Install the heat shield (603) and bolts (604).

Tighten: Tighten the heat shield bolts to 9 N.m (80 lb in).

2. Install the exhaust pipe studs (605).

Tighten: Tighten the studs to 20 N.m (15 lb ft).

Fig. 88: Exhaust Manifold
Courtesy of GENERAL MOTORS CORP.

Do not apply sealant to the first 3 threads of the bolt.

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

3. Apply a 5 mm (0.2 in) wide band of threadlock GM P/N 12345493 (Canadian P/N

10953488), or equivalent, to the threads of the exhaust manifold bolts. Refer to Sealers,
Adhesives, and Lubricants .

4. Install the exhaust manifold, NEW gasket, and bolts.

Tighten:

1. Tighten the exhaust manifold bolts a first pass to 15 N.m (11 lb ft). Tighten the exhaust

manifold bolts beginning with the center 2 bolts. Alternate from side-to-side, and work
toward the outside bolts.

2. Tighten the exhaust manifold bolts a final pass to 20 N.m (15 lb ft). Tighten the

exhaust manifold bolts beginning with the center 2 bolts. Alternate from side-to-side,
and work toward the outside bolts.

5. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the rear of

the left cylinder head.

EXHAUST MANIFOLD INSTALLATION - RIGHT SIDE

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. 89: Exhaust Manifold
Courtesy of GENERAL MOTORS CORP.

NOTE:

Refer to Fastener Notice .

IMPORTANT:

Tighten the exhaust manifold bolts as specified in the
service procedure. Improperly installed and/or leaking
exhaust manifold gaskets may affect vehicle emissions
and/or on-board diagnostic (OBD) II system performance.

The cylinder head exhaust manifold bolt hole threads
must be clean and free of debris or threadlocking

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. Install the heat shield (603) and bolts (604).

Tighten: Tighten the heat shield bolts to 9 N.m (80 lb in).

2. Install the exhaust pipe studs (605).

Tighten: Tighten the studs to 20 N.m (15 lb ft).

Fig. 90: Exhaust Manifold

material.

Do not apply sealant to the first 3 threads of the bolt.

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