Intake Manifold: Service and Repair

REMOVAL
UPPER INTAKE MANIFOLD
1. Disconnect negative cable from battery.
2. Remove front engine compartment supports and upper radiator crossmember.
3. Remove air cleaner intake duct.
4. Remove throttle and speed control cables from throttle arm and bracket.
5. Disconnect electrical connectors from the following sensors:
- Manifold Tuning Valve (MTV)
- Throttle Position Sensor (TPS)
- Idle Air Control (IAC)
- Intake Air Temperature/Manifold Absolute Pressure (TMAP)
6. Disconnect vacuum hoses from the following:
- Secondary Runner Valve (SRV) solenoid
- Speed Control Reservoir
- Positive Crankcase Ventilation (PCV) Valve
- Brake booster
- Proportional purge solenoid








7. Remove right side (Fig. 121) and left side (Fig. 122) intake manifold supports.





8. Remove support brackets at intake manifold front corners and at MTV (Fig. 123).
9. Remove clips attaching EGR tubes to intake manifold.





10. Remove bolts attaching intake manifold and remove manifold (Fig. 124).

LOWER

WARNING: RELEASE FUEL SYSTEM PRESSURE BEFORE SERVICING SYSTEM COMPONENTS. SERVICE VEHICLES IN WELL VENTILATED AREAS AND AVOID IGNITION SOURCES. NEVER SMOKE WHILE SERVICING THE VEHICLE.

1. Perform fuel pressure release.
2. Drain cooling system.
3. Remove upper intake manifold.
4. Disconnect electrical connectors to fuel injectors and coolant temperature sensor.
5. Disconnect heater supply and coolant bottle hoses from heater tube at rear of manifold.
6. Disconnect fuel supply hose from fuel rail.
7. Remove bolts attaching fuel rail.
8. Remove fuel rail and injectors as an assembly.
9. Remove bolts attaching lower intake and remove intake manifold.

CLEANING
Clean the mating surfaces of the cylinder head and intake manifold.

CAUTION: Do not use a metal scraper to remove gasket material on aluminum surfaces. Instead, use a wooden or plastic scraper.

INSPECTION
Check for:
- Damage and cracks of each section.
- Upper and lower intake manifold gasket surfaces for flatness.
- Clogged water passages in end cross over.

INSTALLATION
UPPER
1. Clean and inspect gasket sealing surfaces.

NOTE: Intake gaskets can be reused, provided they are free of cuts, tears, or deformation.

2. Inspect gasket for cuts, tears, or deformation. Replace gaskets as necessary.
3. Install intake manifold and hand start all attaching bolts (Fig. 124).





4. Tighten bolts gradually in sequence shown in (Fig. 125) until a torque of 12 Nm (105 in. lbs.) is obtained.
5. Install right side (Fig. 121) and left side (Fig. 122) intake manifold supports. Tighten bolts to 28 Nm (250 in. lbs.).
6. Install manifold support brackets at front corners and at MTV (Fig. 123). Tighten fasteners to 12 Nm (105 in. lbs.).
7. Connect vacuum lines to: Secondary Runner Valve, Speed Control Reservoir, Positive Crankcase Ventilation (PCV) Valve, Brake Booster, and Proportional Purge Solenoid.
8. Connect electrical connectors to: Intake Air Temperature/Manifold Absolute Pressure (TMAP), Idle Air Control (IAC), Throttle Position Sensor (TPS), and Manifold Tuning Valve (MTV).
9. Install EGR tubes to intake manifold.
10. Install throttle and speed control cables to bracket and throttle arm.
11. Install air intake duct.
12. Install upper radiator crossmember and front engine compartment supports.
13. Connect negative cable to battery.

LOWER
1. Clean all sealing surfaces.

NOTE: Gaskets can be reused provided they are free of tears, cuts, or deformation.

2. Inspect gaskets for tears, cuts, or deformation. Replace as necessary.





3. Position gasket and intake manifold on cylinder head surfaces (Fig. 126).
4. Install fuel rail with injectors.





5. Install intake manifold bolts, and gradually tighten in sequence shown in (Fig. 127) until a torque of 28 Nm (250 in. lbs.) is obtained.
6. Connect fuel supply hose to fuel rail.
7. Connect heater hose to heater tube at rear of manifold.
8. Connect electrical connectors to fuel injectors and coolant temperature sensor.
9. Install upper intake manifold.
10. Fill cooling system.
11. With the DRB scan tool use ASD Fuel System Test to pressurize system to check for leaks.

CAUTION: When using the ASD Fuel System Test, the Auto Shutdown (ASD) relay will remain energized for 7 minutes or until the ignition switch is turned to the OFF position, or Stop All Test is selected.