Installation Procedure

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Install the heat shield (2), and bolts (1) to the exhaust manifold (1), if necessary.
NOTE: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Tighten

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

Fig 1: Installing Heat Shield Bolts, And Shield From Exhaust Manifold
Courtesy of GENERAL MOTORS CORP.

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 Diagnostics (OBD) II system performance.
- The cylinder head exhaust manifold bolt hole threads must be clean and free of debris or threadlocking material.
- Do not apply sealant to the first three threads of the bolt.
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.
Install the exhaust manifold, NEW gasket and bolts.

Fig 2: Installing Exhaust Manifold Bolts, Manifold, And Gasket
Courtesy of GENERAL MOTORS CORP.

Tighten
1. 3.1. Tighten the bolts a first pass to 15 N.m (11 lb ft). Tighten the exhaust manifold bolts beginning with the center two bolts. Alternate from side-to-side, and work toward the outside bolts.
2. 3.2. Tighten the bolts a final pass to 25 N.m (18 lb ft). Tighten the exhaust manifold bolts beginning with the center two bolts. Alternate from side-to-side, and work toward the outside bolts.
Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the front of the right cylinder head.
Install the spark plugs. Refer to SPARK PLUGS in Engine Controls -4.8L, 5.3L, and 6.0L.
Install the ignition coils. Refer to IGNITION COILS in Engine Controls - 4.8L, 5.3L, and 6.0L.
Raise the vehicle.
Install the exhaust manifold pipe nuts.
Tighten

Tighten the nuts to 50 N.m (37 lb ft).

Fig 3: Installing Exhaust Manifold Pipe Nuts

Courtesy of GENERAL MOTORS CORP.

Lower the vehicle.