- 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 NEW exhaust manifold bolts. Refer to Adhesives, Fluids, Lubricants, and Sealers .
- Install the exhaust manifold and NEW exhaust manifold gasket.
- Install the NEW exhaust manifold bolts.
- 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.
- 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.
- Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the rear of the left cylinder head.
- Install the heat shield (2) and bolts (3).
Important:
• Tighten the NEW 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. • Do not apply sealant to the first 3 threads of the bolt.
Notice: 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
Tighten the heat shield bolts to 9 N·m (80 lb in).
