GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2003 🢒 Rendezvous - FWD 🢒 Engine 🢒 Engine Electrical 🢒 Lower Intake Manifold Replacement

Removal Procedure
  1. Remove the upper intake manifold. Refer to Upper Intake Manifold Replacement .
  2. Remove the engine left side valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement - Left Side .
  3. Remove the engine right side valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement - Right Side .

    4. Object Number: 190517 Size: SH
  4. Disconnect the wiring harness from the engine coolant temperature (ECT) sensor.

    5. Object Number: 261255 Size: SH

    Important: Use masking tape or another appropriate method in order to identify each fuel injector wiring harness connector cylinder number.

  5. Disconnect and remove the fuel injector, manifold air pressure (MAP) and ECT wiring harness.
  6. Remove the fuel feed and return pipe from the fuel injector rail. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls - 3.4L.

    7. Object Number: 187065 Size: SH
  7. Remove the fuel feed and return pipe retaining clip bolt.
  8. Remove the fuel feed and return pipe retaining clip.

    9. Object Number: 862487 Size: SH
  9. Remove the fuel injector rail bolts.
  10. Remove the fuel injector rail with the fuel injectors.

    11. Important: Do NOT disconnect the power steering pipes or hoses from the power steering pump.

  11. Remove the power steering pump from the front engine cover and reposition. Refer to Power Steering Pump Replacement in Power Steering System.
  12. Disconnect the heater inlet pipe with heater hose from the lower intake manifold and reposition. Refer to Heater Inlet Pipe Replacement in Heating, Ventilation and Air Conditioning.
  13. Disconnect the inlet radiator hose from the engine. Refer to Radiator Inlet Hose Replacement in Engine Cooling.

    14. Object Number: 261263 Size: SH
  14. Disconnect the thermostat bypass hose from the lower intake manifold pipe.

    15. Object Number: 261264 Size: SH
  15. Remove the lower intake manifold bolts and discard the bolts.

    16. Object Number: 261265 Size: SH
  16. Remove the lower intake manifold.
  17. Loosen the valve rocker arms and remove the push rods. Refer to Valve Rocker Arm and Push Rod Removal .
  18. Remove the lower intake manifold gaskets and seals.
  19. Clean the lower intake manifold gasket and seal surfaces on the cylinder heads and the engine block.
  20. Clean and inspect the lower intake manifold. Refer to Lower Intake Manifold Cleaning and Inspection .
  21. If you are replacing the lower intake manifold, perform the following steps:
    22. • Remove the ECT sensor. Refer to Engine Coolant Temperature Sensor Replacement in Engine Controls - 3.4L.
    • Remove the thermostat. Refer to Engine Coolant Thermostat Replacement in Engine Cooling.

Installation Procedure
  1. If you are replacing the lower intake manifold, perform the following steps.
    2. • Install the ECT sensor. Refer to Engine Coolant Temperature Sensor Replacement in Engine Controls - 3.4L.
    • Install the thermostat. Refer to Engine Coolant Thermostat Replacement in Engine Cooling.

    Object Number: 843417 Size: SH

    Important: All gasket-mating surfaces need to be free of oil, and foreign material. Use GM P/N 12346139 (Canadian P/N 10953463) or equivalent to clean surfaces.

  2. Install the lower intake manifold gaskets.
  3. Install the push rods and tighten the valve rocker arms. Refer to Valve Rocker Arm and Push Rod Installation .
  4. With the gaskets in place apply a small drop 8-10 mm (0.31-0.39 in) of RTV sealer GM P/N 12346141 (Canadian P/N 89022195) or equivalent to the 4 corners of the intake manifold to block joint (1).
  5. Connect the 2 small drops with a bead of RTV sealer that is between 8-10 mm (0.31-0.39 in) wide and 3.0-5.0 mm (0.12-0.20 in) thick (2).
  6. Install the lower intake manifold.

    7. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 190523 Size: SH

    Important: All lower intake manifold bolts need to be cleaned and free of any foreign material, only new bolts are to be used.

    Important: Manufacturer recommends the center bolts be fully torqued before the diagonal bolts to assure proper seal ability.

    Important: Lower intake manifold bolts in location 6 and 7 should be torqued to specification using a crows foot type tool.

  7. Install NEW lower intake manifold bolts.

    8. Tighten

    1. Tighten the vertical lower intake manifold bolts (1) to 7 N·m (62 lb in).
    2. Tighten the diagonal lower intake manifold bolts (2) to 7 N·m (62 lb in).
    3. Tighten the vertical lower intake manifold bolts (1) to 13 N·m (115 lb in).
    4. Tighten the diagonal lower intake manifold bolts (2) to 25 N·m (18 lb ft).

    Object Number: 261263 Size: SH
  8. Connect the thermostat bypass hose to the lower intake manifold pipe.
  9. Connect the inlet radiator hose to the engine. Refer to Radiator Inlet Hose Replacement in Engine Cooling.
  10. Connect the heater inlet pipe to the lower intake manifold. Refer to Heater Inlet Pipe Replacement in Heating, Ventilation and Air Conditioning.
  11. Install the power steering pump to the front engine cover. Refer to Power Steering Pump Replacement in Power Steering System.

    12. Object Number: 862487 Size: SH
  12. Install the fuel injector rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.4L.
  13. Connect the fuel feed and return pipe to the fuel injector rail. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls - 3.4L.

    14. Object Number: 187065 Size: SH
  14. Install the fuel feed and return pipe retaining clip.
  15. Install the fuel feed and return pipe retaining clip bolt.

    16. Tighten
    Tighten the fuel feed and return pipe retaining clip bolt to 8 N·m (71 lb in).


    Object Number: 261255 Size: SH

    Important: The fuel injector wiring harness connectors must be connected to their respective fuel injectors. Failure to connect the fuel injector connectors to their respective fuel injectors may result in excessive exhaust emissions and poor engine performance.

  16. Install and connect the fuel injector, MAP and ECT wiring harness.

    17. Object Number: 190517 Size: SH
  17. Install the wiring harness to the ECT sensor.
  18. Install the engine right side valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement - Left Side .
  19. Install the engine left side valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement - Left Side .
  20. Install the upper intake manifold. Refer to Upper Intake Manifold Replacement .