Exhaust Manifold Replacement - Left

Exhaust Manifold Replacement - Left (4.8L, 5.3L, and 6.0L- Engines)

Removal Procedure





1. Remove the ignition coils.
2. Remove the spark plugs.
3. Raise and suitably support the vehicle.
4. Remove the exhaust manifold pipe nuts.
5. Lower the vehicle.





6. Remove the exhaust manifold bolts, manifold, and gasket.
7. Discard the gasket.





8. Remove the heat shield bolts (3), and shield (2) from the exhaust manifold (1), if necessary.
9. Clean and inspect the exhaust manifold, if the manifold is not being replaced.


Installation Procedure





Notice: Refer to Fastener Notice in Cautions and Notices.

1. Install the heat shield (2), and bolts (3) to the exhaust manifold (1), if necessary.
- Tighten the bolts to 9 Nm (80 inch lbs.).





Important:
- Tighten the 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 Diagnostics (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 three threads of the bolt.

2. Apply a 5 mm (0.2 inch) wide band of threadlock GM P/N 12345493 or equivalent to the threads of the exhaust manifold bolts.
3. Install the exhaust manifold, NEW gasket and bolts.
3.1. Tighten the exhaust manifold bolts a first pass to 15 Nm (11 ft. lbs.). Tighten the exhaust manifold bolts beginning with the center two bolts. Alternate from side-to-side, and work toward the outside bolts.
3.2. Tighten the exhaust manifold bolts a final pass to 25 Nm (18 ft. lbs.). Tighten the exhaust manifold bolts beginning with the center two bolts. Alternate from side-to-side, and work toward the outside bolts.
4. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the rear of the left cylinder head.
5. Raise the vehicle.





6. Install the exhaust manifold pipe nuts.
- Tighten the nuts to 50 Nm (37 ft. lbs.).
7. Lower the vehicle.
8. Install the spark plugs. Refer to Spark Plug Replacement in Engine Controls -4.8L, 5.3L, and 6.OL.
9. Install the ignition coils. Refer to Ignition Coil(s) Replacement in Engine Controls - 4.8L, 5.3L, and 6.OL.