For 1990-2009 cars only
- 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 and NEW exhaust manifold gasket.
- Install the exhaust manifold bolts.
- Tighten the exhaust manifold bolts a first pass to 15 N·m (12 lb ft). Tighten the exhaust manifold bolts beginning with the center two bolts. Alternate from side-to-side, and work toward the outside bolts.
- 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.
- Install the heat shield (603) and bolts (604).
Important:
• Tighten the exhaust manifold bolts as specified in the service procedure.
Improperly installed and/or leaking exhaust manifold gaskets may effect 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.
Refer to Sealers, Adhesives, and Lubricants .
Notice: Refer to Fastener Notice in the Preface section.
Tighten
Tighten
Tighten the heat shield bolts to 9 N·m (80 lb in).
