89. Exhaust Manifold Installation - Left
Exhaust Manifold Installation - Left1. 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 material.
Important:
Do not apply sealant to the first three threads of the bolt.
Apply a 5 mm (0.2 inch) 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.
2. Install the exhaust manifold and NEW exhaust manifold gasket.
3. Notice:
Refer to Fastener Notice in Service Precautions.
Install the exhaust manifold bolts.
1. Tighten the exhaust manifold bolts a first pass to 15 Nm (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. Tighten the exhaust manifold bolts a final pass to 25 Nm (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.
4. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the rear of the left cylinder head.
5. Install the heat shield (603) and bolts (604).
^ Tighten the heat shield bolts to 9 Nm (80 lb in).