Exhaust Manifold Replacement - Left Side

Exhaust Manifold Replacement - Left 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 exhaust crossover pipe heat shield in order to access the cross pipe to the exhaust manifold nuts.
3. Remove the exhaust crossover pipe nuts from the left exhaust manifold.
4. Remove the left side spark plugs. Refer to Spark Plug Replacement (Service and Repair).
5. Remove the oil level indicator tube. Refer to Oil Level Indicator and Tube Replacement (Service and Repair).




6. Remove the exhaust manifold heat shield bolts (604).
7. Remove the exhaust manifold heat shield (603).
8. Remove the heater hose retainer bolts in order to be able to remove the manifold.




9. Remove the exhaust manifold bolts.
10. Remove the exhaust manifold.
11. 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 left 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 oil level indicator tube. Refer to Oil Level Indicator and Tube Replacement (Service and Repair).
7. Install the left side spark plugs. Refer to Spark Plug Replacement (Service and Repair).




8. Install the exhaust crossover pipe nuts from the left exhaust manifold.

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

9. Install the exhaust crossover pipe heat shield.
10. Install the heater pipe retainer bolts.

Tighten the bolts to 16 Nm (12 lb ft).

11. Install the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement (Service and Repair).