Exhaust Manifold Installation - Left Side W/O RPO NC1 or NF7

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.

1. If the engine is equipped with coolant heaters, install the left side (1) heater as follows:

1.1.	Place the coolant heater (1) in position on the cylinder block.

1.2.	Install the coolant heater bolt.

Tighten
Tighten the coolant heater bolt to 10 N·m (89 lb in).




2. With the manifold still on the bench, position a new manifold gasket (1) in place on the manifold sealing surface.
3. Install 2 outer manifold bolts (6) in the manifold to retain the gasket.
4. Install a new manifold to intermediate pipe flange gasket (5).
5. Using 2 hands, place the manifold (2) in the intermediate pipe and onto the cylinder head.
6. Install new manifold flange bolts (3) for maximum joint integrity. Hand tighten. Do not torque the flange bolts to specification until the engine is mounted in the vehicle.
7. Hand tighten the 2 outer manifold bolts.
8. Install the remaining manifold bolts.

Tighten
Tighten the exhaust manifold bolts (6) to 25 N·m (18 lb ft).




9. Coat the oxygen sensor threads with high temperature anti-seize, GM P/N 12377953 or equivalent.
10. Install the oxygen sensor (1).

Tighten
Tighten the oxygen sensor to 40 N·m (30 lb ft).

Exhaust Manifold Installation - Left Side With RPO NC1 or NF7

Notice: Refer to Fastener Notice in the Preface section.




1. If the engine is equipped with coolant heaters, install the left side (1) heater as follows:

1.1.	Place the coolant heater (1) in position on the cylinder block.

1.2.	Install the coolant heater bolt.

Tighten
Tighten the coolant heater bolt to 10 N·m (89 lb in).





Important: DO NOT reuse the exhaust manifold gasket.

2. With the manifold still on the bench, position a new manifold gasket (1) in place on the manifold sealing surface.
3. Install 2 outer manifold bolts (6) in the manifold to retain the gasket.
4. Install a new manifold to intermediate pipe flange gasket (5).
5. Using 2 hands, place the manifold (2) in the intermediate pipe and onto the cylinder head.
6. Install new manifold flange bolts (3) for maximum joint integrity. Hand tighten. Do not torque the flange bolts to specification until the engine is mounted in the vehicle.
7. Hand tighten the 2 outer manifold bolts.
8. Install the remaining manifold bolts.

Tighten
Tighten the exhaust manifold bolts  (6) to 25 N·m (18 lb ft).




9. Coat the oxygen sensor threads with high temperature anti-seize, GM P/N 12377953 or equivalent.
10. Install the oxygen sensor (1).

Tighten
Tighten the oxygen sensor to 40 N·m (30 lb ft).





Important: DO NOT reuse the old secondary air injection (AIR) valve pipe gasket.

11. Install the NEW AIR valve pipe gasket.
12. Install the AIR valve.
13. Install the AIR valve nuts to the mounting bracket.

Tighten
Tighten the AIR valve nuts to 9 N·m (80 lb in).

14. Install the AIR valve bolt through the mounting bracket.

Tighten
Tighten the AIR valve bolt to 9 N·m (80 lb in).

15. Install the AIR valve pipe nuts to the exhaust manifold.

Tighten
Tighten the AIR valve pipe nuts to 9 N·m (80 lb in).