Intake Manifold
Removal & Installation
4.2L Engine
CAUTION
Fuel injection systems remain under pressure, even after the engine has been turned OFF. The fuel system pressure must be relieved before disconnecting any fuel lines. Failure to do so may result in fire and/or personal injury.
- Before servicing the vehicle, refer to the Precautions Section.
- Remove or disconnect the following:NOTERemove the lower intake manifold with the fuel injection supply manifold and fuel injectors as one unit.Engine air cleaner outlet tubeIgnition coil electrical connectorRadio ignition interference capacitor electrical connectorSpark plug wiresAccelerator control splash shieldAccelerator cable end, if equipped, the speed control actuator cable endAccelerator cable and actuator cable aside, after removing the hold-down boltsVapor Management Valve (VMV) hoseBrake booster vacuum hoseManifold vacuum connectionPositive Crankcase Ventilation (PCV) valve from the rocker arm coverEngine Vacuum Regulator (EVR) bracket asideThrottle Position (TP) sensor and Idle Air Control (IAC) valve electrical connectorsBreather from the rocker arm coverThe 12 upper intake manifold retaining bolts, then lift the manifold off of the engine and discard the intake manifold upper gasket.The 6 fuel injector electrical connectorsThe engine coolant temperature sensor and the water temperature indicator sending unit electrical connectors.Exhaust Gas Recirculation (EGR) valve vacuum hoseEGR valve tube upper fittingRadiator hose from the lower intake manifoldIntake Manifold Runner Control (IMRC) actuator brackets asideFuel pressure regulator vacuum lineFuel system pressureFuel linesWater pump bypass hoseThe 6 long bolts and the 8 short bolts, then lift the lower intake manifold off of the engine.
- Remove and discard the lower intake manifold sealing components.
To install:
- Clean all components of dirt, grease and old gasket material.
- Install the lower intake manifold front and rear end seals as follows:
- Apply a bead of RTV sealant to the intake manifold front and rear end seal mounting points.
- Install the lower intake manifold front and rear end seals.
- Install new lower intake manifold gaskets onto the cylinder heads.NOTEThe lower intake manifold must be installed within 15 minutes of applying sealant.
- Apply a bead of RTV silicone gasket sealant to the end of the lower intake manifold end seals, where they stop on the cylinder head surface. Position the intake manifold onto the engine block and cylinder heads.
- Install the lower intake manifold mounting bolts in the correct positions. Refer to the illustration for the correct placement of the long (A) and the short (B) mounting bolts.NOTEBe sure to tighten the intake manifold bolts in 2 steps.
- Tighten the lower intake manifold mounting bolts following the tightening sequence:
- Step 1: 44 inch lbs. (5 Nm).
- Step 2: 71-101 inch lbs. (8.0-11.5 Nm).
- Install or connect the following:NOTEBe sure to tighten the upper intake manifold bolts in the sequence shown.Water bypass hoseFuel linesFuel pressure regulator vacuum lineIMRC actuators. Tighten the bolts on the brackets to 71-102 inch lbs. (8.0-11.5 Nm).Upper radiator hose to the lower intake manifoldEGR valve vacuum hoseEGR tube upper fitting to 25-34 ft. lbs. (37-47 Nm).Engine coolant temperature sensor and water temperature indicator sending unit electrical connectorsThe 6 fuel injector electrical connectorsA new intake manifold upper gasket
- Position the upper intake manifold onto the lower intake manifold, then tighten the upper intake manifold bolts following the tightening sequence as follows:53 inch lbs. (6 Nm).89 inch lbs. (10 Nm).
- Install or connect the following:Breather into the rocker arm coverTP sensor and IAC valve electrical connectorsEVR bracketManifold vacuum connectionPCV valveBrake booster vacuum hoseVapor Management Valve (VMV) hoseAccelerator and speed actuator cablesAccelerator control splash shieldSpark plug wiresIgnition coil and the radio ignition interference capacitor electrical connectorsEngine air cleaner outlet tube
CAUTION
Fuel injection systems remain under pressure, even after the engine has been turned OFF. The fuel system pressure must be relieved before disconnecting any fuel lines. Failure to do so may result in fire and/or personal injury.
- Before servicing the vehicle, refer to the Precautions Section.
- Remove the upper intake manifold.
- Remove or disconnect the following:NOTERemove the lower intake manifold with the fuel injection supply manifold and fuel injectors as one unit.The 6 fuel injector electrical connectorsThe engine coolant temperature sensor and the water temperature indicator sending unit electrical connectorsExhaust Gas Recirculation (EGR) valve vacuum hoseEGR valve tube upper fittingRadiator hose from the lower intake manifoldIntake Manifold Runner Control (IMRC) actuator brackets asideFuel pressure regulator vacuum lineFuel system pressureFuel linesWater pump bypass hoseThe 6 long bolts and the 8 short bolts, then lift the lower intake manifold off of the engine.
- Remove and discard the lower intake manifold sealing components.
To install:
- Clean all components of dirt, grease and old gasket material.
- Install the lower intake manifold front and rear end seals as follows:
- Apply a bead of RTV sealant to the intake manifold front and rear end seal mounting points.
- Install the lower intake manifold front and rear end seals.
- Install new lower intake manifold gaskets onto the cylinder heads.NOTEThe lower intake manifold must be installed within 15 minutes of applying sealant.
- Apply a bead of RTV silicone gasket sealant to the end of the lower intake manifold end seals, where they stop on the cylinder head surface. Position the intake manifold onto the engine block and cylinder heads.
- Install the lower intake manifold mounting bolts in the correct positions. Refer to the illustration for the correct placement of the long (A) and the short (B) mounting bolts.NOTEBe sure to tighten the intake manifold bolts in 2 steps.
- Tighten the lower intake manifold mounting bolts following the tightening sequence:
- Step 1: 44 inch lbs. (5 Nm).
- Step 2: 71-101 inch lbs. (8.0-11.5 Nm).
- Install or connect the following:Water bypass hoseFuel linesFuel pressure regulator vacuum lineIMRC actuators. Tighten the bolts on the brackets to 71-102 inch lbs. (8.0-11.5 Nm).Upper radiator hose to the lower intake manifoldEGR valve vacuum hoseEGR tube upper fitting to 25-34 ft. lbs. (37-47 Nm).Engine coolant temperature sensor and water temperature indicator sending unit electrical connectorsThe 6 fuel injector electrical connectors
- Install the upper intake manifold.
- Before servicing the vehicle, refer to the Precautions Section.
- Remove the air cleaner assembly.
- Remove the engine cover.
- Disconnect the ignition coil electrical connections. WARNINGSpark plug wires must be connected to the correct ignition coil terminal. Mark locations before removing spark plug wires.
- Disconnect and remove the spark plug wires.
- Disconnect the cables, hoses and wiring at the throttle body.
- Remove the accelerator cable bracket.
- Disconnect the brake booster vacuum hose and remove the throttle cable/speed control routing clip retaining screw.
- Disconnect the manifold vacuum connection.
- Disconnect the heated PCV.
- Remove the positive crankcase ventilation (PCV) valve.
- Remove the transmission dipstick tube routing bracket retaining nut and solenoid mounting bracket.
- Remove the two engine vacuum regulator EGR transducer bracket stud bolts.
- Position the EGR transducer bracket aside.
- Disconnect the wiring at the idle air control valve (IAC valve).
- Remove nuts and set vapor management valve aside.
- Remove the bolts and the upper intake manifold.
- Remove and discard the intake manifold upper gasket.
To install:
Upper intake manifold torque sequence 4.2L engine
- To install, reverse the removal procedure. Install a new intake manifold upper gasket. Tighten the bolts in the sequence shown in two stages:Step 1: Tighten to 8 Nm (71 inch lbs.).Step 2: Tighten an additional 90 degrees.
Assembly
- Before servicing the vehicle, refer to the Precautions Section.
- Position a new lower intake manifold gasket and the upper intake manifold on the lower intake manifold and loosely install the bolts.
- Tighten the bolts in two stages using the sequence shown.Stage 1: Tighten to 2 Nm (18 inch lbs.).Stage 2: Tighten to 10 Nm (89 inch lbs.).
- Install the engine noise shield.NOTELubricate the O-ring seals with clean engine oil, to aid installation.
- Install the fuel injectors into the fuel injection supply manifold.
- Install the fuel injection supply manifold. Torque to 89 inch lbs. (10 Nm).
- Before servicing the vehicle, refer to the Precautions Section.
- Remove the fuel infection supply manifold.
- Remove the fuel injectors from the fuel injection supply manifold.
- Inspect the two O-ring seals from each fuel injector. Install new O-ring seals as needed.
- Remove the engine noise shield.
- Remove the bolts.
- Separate the upper and lower intake manifolds and discard the lower intake manifold gasket.WARNINGIf the engine has been internally damaged and metal or other foreign material has entered the manifold, it is recommended the manifold be discarded.NOTEIf there is no residual gasket material present, metal surface prep can be used to clean and prepare the sealing surfaces.
- Inspect all external and internal surfaces of the upper intake manifold. Inspect for cracks or other damage. Inspect for foreign material inside of the manifold. Clean the upper intake manifold sealing surfaces with silicone gasket remover and metal surface prep. Follow the directions on the packaging.
- Allow the upper and lower intake manifolds to dry completely.
WARNING
Do not use metal scrapers, power abrasive discs or any abrasive means to clean the sealing surfaces, these tools cause scratches and gouges that make leak paths. Use a plastic scraper only.
- Before servicing the vehicle, refer to the Precautions Section.
- Clean all the sealing surfaces.
- Position new gaskets and install the intake manifold assembly. Loosely install the nine bolts.
- Connect the intake manifold tuning valve electrical connector.
- Install the thermostat.
- Install the thermostat.
- Install a new O-ring seal.NOTEThe thermostat housing bolts are tightened in sequence with the intake manifold bolts.
- Install the thermostat housing and loosely install the bolts.
- Tighten the 11 bolts in two stages in the sequence shown.Stage 1: Tighten to 2 Nm (18 inch lbs.).Stage 2: Tighten to 25 Nm (18 ft. lbs.).
- Position the generator and install the lower mounting bolts.
- Install the generator upper mounting bracket. Torque to 89 inch lbs. (10 Nm).
- Rotate the belt tensioner clockwise and install the drive belt. Refer to the decal on the radiator upper air deflector for belt routing.
- Connect the eight fuel injector electrical connectors.
- Install and connect eight ignition coils.
- Install the power steering reservoir upper mounting bracket. Torque the 2 upper bolts to 13 ft. lbs. (17 Nm); the one lower bolt to 96 inch lbs. (11 Nm).
- Roughly position the throttle body adapter in the vehicle and connect the heated throttle body hose.
- Install a new gasket, the throttle body adapter and the bolts. Torque to 89 inch lbs. (10 Nm).
- Connect the PCV hose.
- Connect the heater hose and the heated throttle body inlet hose.
- Install the exhaust manifold to EGR valve tube. Hand-tighten the fittings. Tighten the upper and lower fittings to 26-33 ft. lbs. (35-45 Nm).
- Connect the fuel hose spring lock couplings.
- Connect the brake booster vacuum tube and bracket and install the nut.
- Roughly position the vacuum harness and connect the evaporative emission canister purge valve vacuum hose.
- Connect the differential pressure feedback EGR system electrical connector.
- Connect the fuel pressure regulator vacuum hose.
- Connect the evaporative emission canister purge valve hose and the EGR valve vacuum hose.
- Connect the TP sensor and IAC electrical connectors.
- Connect the EGR vacuum regulator solenoid connections.
- Install the IAC fresh air hose.
- Connect the main vacuum harness.
- Install the accelerator cable bracket and the bolts.
- Connect the accelerator cable.
- Connect the speed control actuator cable.
- Install the throttle return spring.
- Connect the upper radiator hose and position the clamp.
- Install the air cleaner outlet pipe.
- Connect the battery ground cable.
- Fill and bleed the engine cooling system.
- Before servicing the vehicle, refer to the Precautions Section.
- Disconnect the battery ground cable.
- Remove the air cleaner outlet pipe.
- Drain the engine cooling system.
- Compress and slide the hose clamp and disconnect the upper radiator hose.
- Disconnect the accelerator cable.
- Disconnect the speed control actuator cable.
- Remove the accelerator return spring.
- Remove the accelerator cable bracket bolts and position the bracket and cables aside.
- Disconnect the main vacuum harness.
- Remove the idle air control (IAC) fresh air hose.
- Disconnect the exhaust gas recirculation (EGR) vacuum regulator solenoid connections.
- Disconnect the IAC and throttle position (TP) sensor electrical connectors.
- Disconnect the EGR valve vacuum hose and the evaporative emission canister purge valve hose and position them aside.
- Disconnect the fuel pressure regulator vacuum hose.
- Disconnect the differential pressure feedback EGR system electrical connector.
- Disconnect the evaporative emission canister purge valve vacuum hose.
- Remove the nut. Disconnect the brake booster vacuum tube and position the bracket and tube aside.
- Position the crankcase ventilation hose aside.
- Position the exhaust manifold to EGR valve tube aside.
- Disconnect the fuel hose spring lock couplings.
- Disconnect the heater hose and the heated throttle body inlet hose.
- Disconnect the positive crankcase ventilation (PCV) hose.
- Remove the four bolts and move the throttle body adapter forward slightly.
- Disconnect the heated throttle body hose and remove the throttle body adapter.
- Discard the throttle body adapter-to-intake manifold gasket. Inspect the throttle body and adapter for damage.
- Remove the power steering reservoir upper mounting bracket.
- Disconnect and remove the eight ignition coils.
- Disconnect the eight fuel injectors.
- Rotate the belt tensioner clockwise and detach the drive belt from the alternator pulley.
- Remove the bolts and the generator upper mounting bracket.
- Remove the generator lower mounting bolts and position the generator aside.
- Remove the bolts, thermostat housing and thermostat. Discard the O-ring seal.
- Remove the nine bolts.
- Lift the intake manifold. Disconnect the intake manifold tuning valve electrical connector. Remove the intake manifold and discard the gaskets. Inspect the intake manifold assembly for damage.
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