REMOVAL & INSTALLATION
All Except SD22, SD25 and VG30i Engines
See Figures 1, 2, 3, 4 and 5
You may find that removing the intake manifold will provide better access to the exhaust manifold on some early models.
- Remove the air cleaner assembly. Remove the heat shield.
- Tag and disconnect the high tension wires from the spark plugs on the exhaust side of the engine.
- Disconnect the exhaust pipe from the exhaust manifold.
If necessary, soak the exhaust pipe retaining bolts with penetrating oil to loosen them.
- On the carbureted models, remove the air induction and/or the EGR tubes from the exhaust manifold. On the Z24i, disconnect the exhaust gas sensor electrical connector.
- Remove the exhaust manifold mounting nuts and then remove the manifold from the cylinder head.
- Using a putty knife, clean the gasket mounting surfaces.
- Install the manifold onto the engine, use new gaskets and, from the center working to the end, tighten the exhaust manifold nuts/bolts to 12-15 ft. lbs. (16-21 Nm)
- Install the air induction and/or the EGR tubes to the exhaust manifold or the exhaust gas sensor electrical connector.
- Reconnect exhaust pipe to the manifold.
- Connect spark plug wires and air cleaner and any related hoses.
- Start engine and check for exhaust leaks.
- Drain the coolant and disconnect the battery cable.
- Tag and disconnect the lines and hoses at the throttle chamber/venturi, dropping resistor and breather. On California SD22 engines, disconnect the EGR pipe at the valve.
- Disconnect and remove the dashpot from the intake manifold on SD22 engines (exhaust manifold-Calif.).
- Remove the intake manifold and then remove the exhaust manifold.
- Scrape any old gasket material off the cylinder head mounting surface and install the manifold using a new gasket. Tighten the bolts gradually, in two or three stages.
- Install the intake manifold.
- Install the dashpot and connect all lines, hoses and pipes.
- Refill the cooling system.
See Figures 6 and 7
- Remove the exhaust manifold sub-cover and manifold cover. Remove the EGR tube from the right side exhaust manifold. Remove the exhaust manifold stay.
- Disconnect the left side exhaust manifold at the exhaust pipe by removing retaining nuts and then disconnect the right side manifold from the connecting pipe.
Soak the exhaust pipe retaining bolts with penetrating oil if necessary to loosen them.
- Remove bolts for each manifold in the order shown.
- Clean all gasket surfaces. Install new gaskets.
- Install the manifold to the engine, tightening the mounting bolts alternately, using two stages of the order shown. Tighten the left side bolts to 13-16 ft. lbs. (18-22 Nm); tighten the right side bolts to 16-20 ft. lbs. (22-27 Nm).
- Reconnect the exhaust pipe and the connecting pipe. Be careful not break these bolts.
- Install the exhaust manifold stay and the EGR tube to the right side manifold.
- Install the exhaust manifold covers. Start the engine and check for exhaust leaks.