Exhaust manifolds — removal and installation


Warning: Use caution when working around the exhaust manifolds — the Sheetmetal heat shields can be sharp on the edges. Also, the engine should be cold when this procedure is followed.

1. Disconnect the cable from the negative terminal of the battery (see Engine electrical systems).

2. Raise the vehicle and support it securely on jack stands.

3. Working under the vehicle, apply penetrating oil to the exhaust pipe-to-manifold studs and nuts (they’re usually rusty) (see illustration).

8.3 Typical exhaust pipe-to-manifold nuts

Chevrolet Silverado V8 engines _ Typical exhaust pipe-to-manifold nuts

4. Remove the inner fender splash shield (see Body).

5. Disconnect the exhaust pipe/catalytic converter pipe from the exhaust manifold.

6. Remove the spark plug wires (see Tune-up and routine maintenance).

Caution: Twist the boots to loosen them, then pull on the boots only — not the wires.

Left side

7. Use a dab of paint to mark the alignment of the upper section of the steering intermediate shaft to the lower part of the steering column (see illustration). Remove the fasteners, then separate the shafts so they can be moved aside.

8.7 The steering shaft should be disconnected for access to the left exhaust manifold; don’t turn the steering wheel or the front wheels after separating it

Chevrolet Silverado V8 engines _ The steering shaft should be disconnected for access to the left exhaust manifold; don't turn the steering wheel or the front wheels after separating it

Caution: Don’t move the wheels or the steering wheel after disconnecting the shafts. The airbag system clock spring could be damaged. Note: On 6.0L models, install special tool J-42640 (steering column anti-rotation pin) into the steering column lower access hole to prevent the column from rotating.

Right side

8. On 6.0L models, remove the oil dipstick tube.

Both sides

9. If a new manifold is to be installed, remove the heat shield (see illustration). Remove the manifold mounting bolts, then lift off the exhaust manifold and its gasket (see illustration).

8.9a Exhaust manifold — heat shield bolts

Chevrolet Silverado V8 engines _ Exhaust manifold - heat shield bolts

8.9b Exhaust manifold mounting bolts

Chevrolet Silverado V8 engines _ Exhaust manifold mounting bolts


10. Check the manifold for cracks and make sure the bolt threads are clean and undamaged. The manifold and cylinder head mating surfaces must be clean before the manifolds are reinstalled — use a gasket scraper to remove all carbon deposits and gasket material.

Note: The cylinder heads are made of aluminum; therefore, aggressive scraping is not suggested and will damage the sealing surfaces.

11. Install the heat shields, then install the bolts and gaskets onto the manifold. Retaining tabs surrounding the gasket bolt holes should hold the assembly together as the manifold is installed.

12. Starting at the fourth thread, apply a 1/4-inch-wide band of medium-strength thread-locking compound to the threads of the bolts. Note: The manufacturer recommends not applying thread locking compound on the first three threads.

13. Place the manifold on the cylinder head and install the mounting bolts finger tight.

14. When tightening the mounting bolts, work from the center to the ends. Tighten the bolts in two steps to the torque listed in this Chapter’s Specifications. If required, bend the exposed end of the exhaust manifold gasket back against the cylinder head.

15. The remainder of installation is the reverse of removal.

16. Start the engine and check for exhaust leaks.

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