Intake Manifold: Service and Repair

REMOVAL
1. Disconnect the battery negative cable.
2. Drain the cooling system.





3. Remove the air inlet hose and resonator from the throttle body and air cleaner housing (Fig. 78).
4. Remove accessory drive belt.
5. Remove the power steering pump and brackets from the water pump and intake manifold. Support power steering pump and bracket with mechanics wire attached to the radiator upper crossmember.
6. Perform the fuel pressure release procedure.
7. Disconnect fuel supply tube from the fuel rail.
8. Disconnect the accelerator cable from the throttle body and cable bracket.
9. Disconnect the speed control and transmission line pressure cable from the throttle body and cable bracket (if equipped).

CAUTION: When disconnecting the speed control connector at the throttle body, DO NOT pry the connector off with pliers or screwdriver. Use finger pressure only. Prying the connector off could break it.

10. Disconnect the electrical connectors. Pull the harnesses away from the manifold.
^ The throttle position sensor.
^ The idle air control motor.
^ The coolant temperature sensor at the thermostat housing. e The manifold air temperature sensor at the intake manifold.
^ The fuel injectors.
^ The oxygen sensor.
11. Disconnect the Crankcase Ventilation (CCV) vacuum hose and Manifold Absolute Pressure (MAP) sensor vacuum hose connector at the intake manifold.
12. Disconnect HVAC supply vacuum hose from intake manifold.
13. Disconnect CCV hose at the cylinder head cover (Fig. 78).
14. Remove the molded vacuum harness.
15. Disconnect the vacuum brake booster hose at the intake manifold.





16. Remove bolts 2 through 5 securing the intake manifold to the cylinder head (Fig. 79). LOOSEN BUT DO NOT REMOVE exhaust manifold bolt No. 1 and nuts 6 and 7.
17. Remove the intake manifold and gaskets. Drain the coolant from the manifold.

CLEANING

CAUTION: DO NOT allow foreign material to enter either the intake manifold ports, or the cylinder head ports.

Clean the intake manifold to cylinder head mating surfaces.

INSPECTION
Inspect manifold to cylinder head mating surfaces for cracks and/or pitting. Inspect manifold for warp or twist.

INSTALLATION
1. Clean the intake manifold and cylinder head mating surfaces. DO NOT allow foreign material to enter either the intake manifold or the ports in the cylinder head.
2. Install the new intake manifold gasket over the locating dowels.
3. Position the manifold in place and finger tighten the mounting bolts.
4. Tighten the fasteners in sequence and to the specified torque (Fig. 79).
^ Fastener No. 1-Tighten to 41 Nm (30 ft. lbs.) torque.
^ Fasteners Nos. 2 through 5-Tighten to 31 Nm (23 ft. lbs.) torque.
^ Fasteners Nos. 6 and 7-Tighten to 23 Nm (17 ft. lbs.) torque.
5. Before connecting the fuel line to the fuel rail inspect the fuel line O-rings and replace them if necessary. Connect the fuel supply tube to the fuel rail inlet.
6. Connect the molded vacuum hoses to the vacuum port on the intake manifold and the cylinder head cover.
7. Connect the electrical connectors.
^ The throttle position sensor.
^ The idle air control motor.
^ The coolant temperature sensor at the thermostat housing.
^ The manifold air temperature sensor at the intake manifold.
^ The fuel injectors.
^ The oxygen sensor.
8. Connect the brake booster vacuum supply hose.
9. Connect the CCV hose and MAP sensor vacuum hose connectors to the throttle body
10. Install the power steering pump and bracket assembly to the water pump and intake manifold. Torque power steering pump bolts to 28 Nm (21 ft. lbs.). Torque bracket to water pump bolts to 47 Nm (35 ft. lbs.).

CAUTION: Ensure that the accessory drive belt is routed correctly. Failure to do so can cause the water pump to turn in the opposite direction resulting in engine overheating.

11. Install the accessory drive belt.
12. Connect the accelerator cable to the bracket and the throttle lever.
13. Connect the speed control and transmission line pressure cable (if equipped) to the bracket and throttle lever.
14. Refill the cooling system.
15. Install the air inlet hose and resonator to the throttle body and the air cleaner.
16. Connect the battery negative cable.
17. Start the engine and check for leaks.