Installation Procedure

Fig 1: View of Exhaust Manifold Fasteners

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.

IMPORTANT: 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.

NOTE: Refer to FASTENER NOTICE in Cautions and Notices.

Install the exhaust manifold, NEW gasket and bolts.
Tighten:
1. Tighten the exhaust manifold bolts a first 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.
2. Tighten the exhaust manifold 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 rear of the left cylinder head.

Fig 2: View Of Left Exhaust Manifold Heat Shield & Bolts

Courtesy of GENERAL MOTORS CORP.

Install the heat shield (2) and bolts (3) to the exhaust manifold (1).
Tighten: Tighten the exhaust manifold heat shield bolts to 9 N.m (80 lb in).
Install the spark plugs. Refer to Spark Plug Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L.
Raise the vehicle.

Fig 3: Exhaust Manifold Pipe Nuts (Left)

Courtesy of GENERAL MOTORS CORP.

Install the exhaust manifold pipe nuts.
Tighten: Tighten the exhaust manifold pipe nuts to 50 N.m (37 lb ft).
Lower the vehicle.