Exhaust Manifold Replacement - Right Side

Exhaust Manifold Replacement - Right Side (LS4-5.3L)

Removal Procedure




1. Remove the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement (Service and Repair).
2. Remove the spark plugs. Refer to Spark Plug Replacement (Service and Repair).
3. Remove the exhaust crossover pipe nuts from the right exhaust manifold.
4. Disconnect the catalytic converter from the exhaust manifold.
5. Support the catalytic convertor and exhaust system with the mechanics wire.
6. Lower the vehicle.
7. Remove the ignition coil. Refer to Ignition Coil Replacement (Service and Repair).
8. Remove the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (Service and Repair).




9. Remove the exhaust manifold heat shield bolts (604).
10. Remove the exhaust manifold heat shield (603).




11. Remove the exhaust manifold bolts.
12. Remove the exhaust manifold.
13. Remove and discard the exhaust manifold gasket.

Installation Procedure

Note:
* Tighten the exhaust manifold bolts as specified in the service procedure. Improperly installed and/or leaking exhaust manifold gaskets my 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 threadlock to the first three thread of the bolts.




1. 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.

Caution: Refer to Fastener Caution (Fastener Caution).

2. Install a NEW exhaust manifold gasket, the exhaust manifold and bolts.

* Tighten the bolts a first pass to 15 Nm (11 lb ft). Tighten the bolts beginning with the center 2 bolts. Alternate from side to side, and work toward the outside.
* Tighten the bolts a final pass to 20 Nm (15 lb ft). Tighten the bolts beginning with the center 2 bolts. Alternate from side to side, and work toward the outside.

3. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the rear of the right cylinder head.




4. Install the exhaust manifold heat shield (603).
5. Install the exhaust manifold heat shield bolts (604).

Tighten the bolts to 9 Nm (80 lb in).

6. Install the O2 sensor. Refer to Spark Plug Replacement (Service and Repair).
7. Raise the vehicle.
8. Remove the mechanics wire from the exhaust system and connect the catalytic converter.




9. Install the exhaust crossover pipe nuts to the right exhaust manifold.

Tighten the nuts to 25 Nm (18 lb ft).

10. Install the ignition coil. Refer to Ignition Coil Replacement (Service and Repair).
11. Install the spark plugs. Refer to Spark Plug Replacement (Service and Repair).
12. Install the fuel injector sight shield. Refer to Upper Intake Manifold Sight Shield Replacement (Service and Repair).