Exhaust Manifold: Service and Repair

Exhaust Manifold Replacement (4.2L Engine)

Removal Procedure

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle (Service and Repair).




2. Loosen and remove the exhaust pipe bolts from the exhaust manifold.
3. Lower the vehicle.
4. Remove the manifold heat shield. Refer to Exhaust Manifold Heat Shield Replacement (Exhaust Manifold Heat Shield Replacement).




5. Loosen and remove the exhaust manifold bolts.
6. Remove the exhaust manifold.
7. Remove the exhaust manifold gasket.

Installation Procedure




1. Install a new exhaust manifold gasket.




2. Install the exhaust manifold.

Caution: Refer to Fastener Caution (Fastener Caution).

3. With threadlock GM P/N 12345493 (Canadian P/N 10953488) on the manifold bolts, install the bolts onto the manifold.

1. Tighten the exhaust manifold bolts first pass in sequence to 20 Nm (15 ft. lbs.).
2. Tighten the exhaust manifold bolts second pass in sequence to 20 Nm (15 ft. lbs.).
3. Tighten the exhaust manifold bolts final pass in sequence to 20 Nm (15 ft. lbs.).




4. Install the exhaust manifold heat shield studs, if required and tighten to 10 Nm (89 in. lbs.).
5. Install the manifold heat shield. Refer to Exhaust Manifold Heat Shield Replacement (Exhaust Manifold Heat Shield Replacement).
6. Raise the vehicle.




7. Install the exhaust pipe to the manifold with seal and secure the pipe with the nuts. Tighten the exhaust pipe nuts to 50 Nm (37 ft. lbs.).
8. Lower the vehicle.