Jeep Wagoneer/Commando/Cherokee 1984-1998

Intake Manifold

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Removal & Installation



2.1L Diesel Engine

See Figure 1

  1. Disconnect the negative battery cable. Disconnect the air inlet hose at the intake manifold.
  2.  



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Fig. Fig. 1: Intake and exhaust manifold used on the diesel engine

  1. Tag and remove all hoses and/or wires as necessary in order to gain access to the intake manifold retaining bolts.
  2.  
  3. Tag and remove all vacuum hoses and electrical connections that are attached to the intake manifold.
  4.  
  5. Remove the intake manifold retaining bolts. Remove the assembly from the vehicle. Discard the intake manifold gaskets.
  6.  

To install:
  1. Clean mating surfaces of all gasket material. Install new gasket.
  2.  
  3. Installation is the reverse of removal. Tighten bolts from center to outside of manifold in steps to 20 ft. lbs. (27 Nm).
  4.  

2.5L Engine
CARBURETED

See Figures 2 and 3

It may be necessary to remove the carburetor from the intake manifold before the manifold is removed.



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Fig. Fig. 2: Intake and exhaust manifold used on the carbureted 2.5L engine

  1. Disconnect the negative battery cable. Drain the radiator.
  2.  


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Remove the air cleaner. Disconnect the fuel pipe. Remove the carburetor.
  2.  
  3. Disconnect the coolant hoses from the intake manifold.
  4.  
  5. Disconnect the throttle cable from the bellcrank.
  6.  
  7. Disconnect the PCV valve vacuum hose from the intake manifold.
  8.  
  9. If equipped, remove the vacuum advance CTO valve vacuum hoses.
  10.  
  11. Disconnect the system coolant temperature sender wire connector (located on the intake manifold). Disconnect the air temperature sensor wire, if equipped.
  12.  
  13. Disconnect the vacuum hose from the EGR valve.
  14.  
  15. On vehicles equipped with power steering remove the power steering pump and its mounting bracket. Do not detach the power steering pump hoses.
  16.  
  17. Disconnect the intake manifold electric heater wire connector, as required.
  18.  
  19. Disconnect the throttle valve linkage, if equipped with automatic transmission.
  20.  
  21. Disconnect the EGR valve tube from the intake manifold.
  22.  
  23. Remove the intake manifold attaching screws, nuts and clamps. Remove the intake manifold. Discard the gasket.
  24.  
  25. Clean the mating surfaces of the manifold and cylinder head.
  26.  

If the manifold is being replaced, ensure all fittings, etc., are transferred to the replacement manifold.

To install:
  1. Clean the mating surfaces of the manifold and cylinder head.
  2.  
  3. Install the intake manifold, with a new gasket. Install intake manifold attaching screws, nuts and clamps. Using the sequence shown in the illustration, tighten the bolts in steps to 23 ft. lbs. (31 Nm).
  4.  



Click image to see an enlarged view

Fig. Fig. 3: Intake and exhaust manifold torque sequence

  1. Connect the EGR valve tube.
  2.  
  3. Connect the throttle valve linkage, if equipped with automatic transmission.
  4.  
  5. Connect the intake manifold electric heater wire connector, as required.
  6.  
  7. On vehicles equipped with power steering install the power steering pump and its mounting bracket.
  8.  
  9. Connect the vacuum hose to the EGR valve.
  10.  
  11. Connect the system coolant temperature sender wire connector (located on the intake manifold).
  12.  
  13. Connect the air temperature sensor wire, if equipped.
  14.  
  15. If equipped, install the vacuum advance CTO valve vacuum hoses.
  16.  
  17. Connect the PCV valve vacuum hose at the intake manifold.
  18.  
  19. Connect the throttle cable at the bellcrank.
  20.  
  21. Connect the coolant hoses at the intake manifold.
  22.  
  23. Install the carburetor and working in a crisscross pattern, tighten the nuts to 14 ft. lbs. (19 Nm).
  24.  
  25. Connect the fuel pipe.
  26.  
  27. Install the air cleaner.
  28.  
  29. Connect the negative battery cable.
  30.  
  31. Fill the cooling system.
  32.  

FUEL INJECTED

See Figures 4, 5, 6, 7, 8, 9 and 10

  1. Disconnect negative battery cable.
  2.  
  3. Remove the air cleaner inlet hose.
  4.  
  5. Loosen the accessory drive belt tension and remove the drive belt.
  6.  
  7. Remove the power steering pump and brackets. Support them from the radiator support with wire.
  8.  
  9. Remove the fuel tank filler cap to relieve the fuel tank pressure. Relieve the fuel system pressure.
  10.  
  11. Disconnect the fuel supply tube from the fuel rail by squeezing the tabs of the quick connector and pulling. When disconnected, the retainer will stay on the fuel tube and the O-rings and spacer will remain in the connector. Use an "L'' shaped paper clip to remove the O-rings and spacer.
  12.  

Whenever a fuel system disconnect fitting is disconnected the O-rings, spacer and retainer must be replaced.

  1. Follow the instructions on the O-ring replacement kit package to install the new O-rings and spacer.
  2.  
  3. Disconnect the accelerator cable from the throttle body and hold-down bracket. Disconnect the cruise control connector (if equipped) by loosening it with your hands. DO NOT attempt to pry off.
  4.  



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Fig. Fig. 4: Disengage the accelerator cable from the throttle body



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Fig. Fig. 5: Remove the cable hold-down bracket from the manifold



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Fig. Fig. 6: Unplug the necessary vacuum hoses ...



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Fig. Fig. 7: ... and electrical connectors from the manifold

  1. Disconnect all necessary electrical connectors:
  2.  



the throttle position sensor
 
Idle speed motor
 
Coolant temperature sensor at the thermostat
 
Manifold air temperature sensor at the intake manifold
 
Fuel injectors
 
Oxygen sensor
 

  1. Disconnect the crankcase ventilation vacuum hose and manifold absolute pressure sensor vacuum hose at the intake manifold. Disconnect the crankcase ventilation hose on the rocker arm cover.
  2.  
  3. Disconnect the vacuum hose at the EGR transducer and solenoid (if necessary).
  4.  
  5. Disconnect the molded vacuum harness.
  6.  
  7. Loosen the EGR tube nut and remove the bolts securing the tube to the exhaust manifold (if necessary).
  8.  
  9. Drain the cooling system.
  10.  


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.



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Fig. Fig. 8: Remove the manifold retaining hardware ...



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Fig. Fig. 9: ... then remove the manifold from the engine

  1. Disconnect the vacuum brake booster hose at the intake manifold.
  2.  
  3. Remove bolts number 2 through 5 securing the intake manifold. Loosen bolt 1 and nuts 6 and 7.
  4.  
  5. Remove the intake manifold.
  6.  

To install:
  1. Clean the intake manifold and cylinder head mating surfaces. DO NOT allow foreign material to enter the intake manifold or cylinder head ports. Install the new intake manifold gasket over the locating dowels.
  2.  



Click image to see an enlarged view

Fig. Fig. 10: Intake and exhaust manifold torque sequence

  1. Position the intake manifold in place and finger-tighten bolts.
  2.  
  3. Use a new EGR tube gasket and attach the EGR tube to the exhaust manifold. Finger-tighten bolts 9 and 10. Leave the EGR tube nut at the intake manifold finger-tight.
  4.  
  5. Tighten the fasteners in sequence and to the specified torque.
  6.  

1985-90 Models



Fasteners 1, 6, 7, and 8: 30 ft. lbs. (41 Nm)
 
Fasteners 2, 3, 4, and 5: 23 ft. lbs. (31 Nm)
 
Fasteners 9 and 10: 14 ft. lbs. (19 Nm)
 

1991-98 Models



Fastener 1: 30 ft. lbs. (41 Nm)
 
Fasteners 2-7: 23 ft. lbs. (31 Nm)
 

  1. Connect the fuel return and supply tube to the connector next to the fuel rail. Don't forget to install the new O-rings. Push them into the fitting until a click is heard. Verify correct installation by first ensuring only the retainer tabs protrude from the connectors and second by pulling out on the fuel tubes to ensure they are locked in place.
  2.  
  3. Attach heater hoses to manifold (if necessary), connect the molded vacuum hoses to the intake manifold, the EGR transducer, the EGR solenoid and the rocker arm cover.
  4.  
  5. Connect electrical connectors previously disconnected.
  6.  
  7. Connect the crankcase ventilation vacuum hose and manifold absolute pressure sensor vacuum hose.
  8.  
  9. Install the power steering pump and bracket assembly to the water pump and intake manifold.
  10.  
  11. Connect the accelerator cable and cruise control cable (if equipped) to the hold-down bracket and throttle arm.
  12.  
  13. Install and tension the accessory drive belt.
  14.  

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

  1. Connect the negative battery cable. Start the engine and check for leaks.
  2.  

2.8L Engine

See Figure 11

It may be necessary to remove the carburetor from the intake manifold before the manifold is removed.

  1. Disconnect the negative battery cable. Remove the air cleaner and rocker arm covers. Drain the coolant.
  2.  


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. If equipped with air conditioning disconnect the compressor and move it to one side. Disconnect the spark plugs wires at the spark plugs. Disconnect the wires at the ignition coil.
  2.  
  3. If equipped, remove the air pump and bracket.
  4.  
  5. Remove the distributor cap. Mark the position of the ignition rotor in relation to the distributor body and remove the distributor. Do not crank the engine with the distributor removed.
  6.  
  7. Remove the EGR valve. Remove the air hose. Disconnect the charcoal canister hoses. Remove the pipe bracket from the left cylinder head, if equipped.
  8.  
  9. Remove the diverter valve. Remove the power brake vacuum hose. Remove the heater and radiator hoses from the intake manifold.
  10.  



Click image to see an enlarged view

Fig. Fig. 11: Intake manifold torque sequence on the 2.8L engine

  1. Disconnect and label the vacuum hoses. If equipped, remove the EFE pipe from the rear of the manifold. Disconnect the coolant temperature switches.
  2.  
  3. Remove the carburetor linkage. Disconnect and plug the fuel line.
  4.  
  5. Remove the manifold retaining bolts and nuts.
  6.  
  7. Remove the intake manifold. Remove and discard the gaskets, and scrape off the old silicone seal from the front and rear ridges.
  8.  

To install:
  1. The gaskets are marked for right and left side installation; do not interchange them. Clean the sealing surface of the engine block, and apply a 0.19 in. (5mm) wide bead of silicone sealer to each ridge.
  2.  
  3. Install the new gaskets onto the heads. The gaskets will have to be cut slightly to fit past the center pushrods. Do not cut any more material than necessary. Hold the gaskets in place by extending the ridge bead of sealer 1 / 4 in. (6mm) onto the gasket ends.
  4.  
  5. Install the intake manifold. The area between the ridges and the manifold should be completely sealed.
  6.  
  7. Install the retaining bolts and nuts, and tighten in sequence to 23 ft. lbs. (31 Nm). Do not overtighten the manifold. It is made of aluminum, and can be warped or cracked with excessive force.
  8.  
  9. Connect the fuel line.
  10.  
  11. Install the carburetor linkage.
  12.  
  13. Connect the vacuum hoses.
  14.  
  15. Install the EFE pipe at the rear of the manifold.
  16.  
  17. Connect the coolant temperature switches.
  18.  
  19. Install the diverter valve.
  20.  
  21. Install the power brake vacuum hose.
  22.  
  23. Install the heater and radiator hoses.
  24.  
  25. Install the EGR valve.
  26.  
  27. Install the air hose.
  28.  
  29. Connect the charcoal canister hoses.
  30.  
  31. Install the pipe bracket at the left cylinder head, if equipped.
  32.  
  33. Install the distributor.
  34.  
  35. Install the distributor cap.
  36.  
  37. Install the air pump and bracket.
  38.  
  39. Connect the air conditioning compressor.
  40.  
  41. Install the rocker arm covers.
  42.  
  43. Connect the spark plugs wires at the spark plugs.
  44.  
  45. Connect the wires at the ignition coil.
  46.  
  47. Connect the negative battery cable.
  48.  
  49. Install the air cleaner.
  50.  
  51. Fill the cooling system.
  52.  

4.0L Engine

The intake and exhaust manifold are mounted externally on the left side of the engine and are attached to the cylinder head. They are removed as a unit. Please refer to the combination manifold procedure.

5.2L and 5.9L Engines

See Figures 12 and 13

  1. Disconnect the negative battery cable.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Drain the cooling system.
  6.  
  7. Remove the air cleaner.
  8.  
  9. Remove the alternator.
  10.  
  11. Remove the fuel lines and fuel rail.
  12.  
  13. Disconnect the accelerator linkage and, if equipped, the cruise control and transmission kickdown cables.
  14.  
  15. Remove the return spring.
  16.  
  17. Remove the distributor cap and wires.
  18.  
  19. Disconnect the coil wires.
  20.  
  21. Disconnect the heat indicator sending unit wire.
  22.  
  23. Disconnect the heater and bypass hoses.
  24.  
  25. Disconnect the PCV and EVAP lines.
  26.  
  27. If equipped with A/C, remove the compressor and position it aside with the lines attached.
  28.  
  29. Remove the support bracket from the mounting bracket and intake manifold.
  30.  
  31. Remove the intake manifold and discard the gaskets.
  32.  
  33. Remove the throttle body and discard the gasket.
  34.  
  35. Turn the intake manifold upside down and support it. Remove the bolts and lift the plenum pan off the manifold. Discard the gasket.
  36.  
  37. Clean all gasket mating surfaces. Clean the intake manifold with solvent and blow dry with compressed air. The plenum pan rail must be clean, dry and free of all foreign material.
  38.  

To install:
  1. Place a new plenum pan gasket onto the seal rail of the intake manifold.
  2.  
  3. Position the pan over the gasket and align the holes. Hand-tighten the bolts.
  4.  
  5. Tighten the bolts as follows:
  6.  

  1. Tighten all bolts, in sequence, to 24 inch lbs. (3 Nm).
  2.  
  3. Tighten all bolts, in sequence, to 48 inch lbs. (5.5 Nm).
  4.  
  5. Tighten all bolts, in sequence, to 84 inch lbs. (10 Nm).
  6.  
  7. Repeat Step c to ensure proper torque.
  8.  

  1. Using a new gasket, install the throttle body onto the intake manifold. Tighten the bolts to 200 inch lbs. (23 Nm).
  2.  



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Fig. Fig. 12: Plenum pan torque sequence



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Fig. Fig. 13: Intake manifold torque sequence

  1. Place the 4 plastic locator dowels into the holes in the block.
  2.  
  3. Apply Mopar rubber adhesive sealant or equivalent, to the 4 corner joints.
  4.  

An excessive amount of sealant is not required to ensure a leak proof seal, however, and excessive amount of sealant may reduce the effectiveness of the flange gasket. The sealant should be slightly higher than the crossover gaskets (approximately 0.2 inch).

  1. Install the front and rear crossover gaskets onto the dowels.
  2.  
  3. Install the flange gaskets. Ensure the vertical port alignment tab is resting on the deck face of the block. Also, the horizontal mating alignment tabs must be in position with the mating cylinder head gasket tabs. The words MANIFOLD SIDE should be visible on the center of each flange gasket.
  4.  
  5. Carefully lower the intake manifold into place. Use the alignment dowels in the crossover gaskets to position the manifold. Once in place ensure the gaskets are still in position.
  6.  
  7. Tighten the manifold bolts in sequence to the following specifications:
  8.  

  1. Bolts 1-4-72 inch lbs. (8 Nm). Tighten in alternating steps to 12 inch lbs. (1.5 Nm)
  2.  
  3. Bolts 5-12-72 inch lbs. (8 Nm)
  4.  
  5. Repeat Steps a and b to ensure proper torque.
  6.  
  7. All bolts-12 ft. lbs. (16 Nm)
  8.  
  9. Repeat Step d to ensure proper torque.
  10.  

  1. Connect the PCV and EVAP lines.
  2.  
  3. Install the coil wires.
  4.  
  5. Connect the heat indicator sending unit wire.
  6.  
  7. Connect the heater and bypass hoses.
  8.  
  9. Install the distributor cap and wires.
  10.  
  11. Hook up the return spring.
  12.  
  13. Connect the accelerator linkage and, if equipped, cruise control and transmission kick down cables.
  14.  
  15. Install the fuel lines and fuel rail.
  16.  
  17. Install the support bracket.
  18.  
  19. Install the alternator and drive belt.
  20.  
  21. If equipped with A/C, install the compressor.
  22.  
  23. Install the air cleaner.
  24.  
  25. Fill the cooling system.
  26.  
  27. Connect the negative battery cable.
  28.  
  29. Start the engine and check for leaks.
  30.  

 
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