GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2003 🢒 Century 🢒 Engine 🢒 Engine Mechanical - 3.1L 🢒 Engine Replacement

Removal Procedure

    Object Number: 96002 Size: SH
  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  2. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  3. Drain the engine oil. Refer to Engine Oil and Oil Filter Replacement .
  4. Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls - 3.1L.
  5. Remove the hood. Refer to Hood Replacement in Body Front End.
  6. Remove the engine mount struts. Refer to Engine Mount Strut Replacement .
  7. Remove the drive belt. Refer to Drive Belt Replacement .
  8. Disconnect the following electrical connectors:
    9. • Knock sensor
    • Camshaft position (CMP) sensor
    • Crankshaft position (CKP) sensor
    • Heated oxygen sensor (HO2S)
    • Manifold absolute pressure (MAP) sensor
    • Exhaust gas recirculation (EGR) valve
    • Evaporative emissions (EVAP) canister purge solenoid
    • Throttle position (T/P) sensor
    • Idle air control (IAC) valve
    • Ignition coil
    • Body wiring harness-to-engine harness
  9. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  10. Remove the 3-way catalytic converter pipe from the right exhaust manifold. Refer to Catalytic Converter Replacement in Engine Exhaust.
  11. Remove the engine wiring harness grounds from the transaxle.
  12. Remove the engine mount lower nuts.
  13. Remove the torque converter covers. Refer to Torque Converter Cover Replacement in Automatic Transaxle - 4T65E.
  14. Remove the starter motor. Refer to Starter Motor Replacement in Engine Electrical.
  15. Remove the A/C compressor. DO NOT discharge the A/C system. Support the compressor. Refer to Air Conditioning Compressor Replacement in Heating, Ventilation, and Air Conditioning.
  16. Remove the torque converter bolts. Refer to Flywheel to Torque Converter Bolt Replacement in Automatic Transaxle - 4T65E.
  17. Remove the transaxle brace. Refer to Transmission Brace Replacement in Automatic Transaxle - 4T65E.

    18. Object Number: 160965 Size: SH
  18. Remove the lower transaxle-to-engine bolt (6) and the stud (1).
  19. Remove the radiator outlet hose from the engine. Refer to Radiator Outlet Hose Replacement in Engine Cooling.
  20. Lower the vehicle and support the transaxle.
  21. Remove the accelerator control and the cruise control cable with the bracket from the throttle body. Refer to Accelerator Control Cable Bracket Replacement in Engine Controls - 3.1L.
  22. Remove the heater outlet and inlet hoses from the engine.
  23. Remove the vacuum hoses from the upper intake manifold.
  24. Remove the brake booster vacuum hose from the upper intake manifold.
  25. Remove the fuel lines from the fuel rail. Refer to Metal Collar Quick Connect Fitting Service and Plastic Collar Quick Connect Fitting Service in Engine Controls - 3.1L.
  26. Remove the radiator inlet hose from the engine. Refer to Radiator Inlet Hose Replacement in Engine Cooling.
  27. Remove the power steering pump and reposition. Refer to Power Steering Pump Replacement in Power Steering System.
  28. Install the engine lifting device to the engine.
  29. Remove the upper transaxle-to-engine bolts (3,4,5) and the stud (2).
  30. Remove the engine from the vehicle.
  31. Remove the flywheel. Refer to Engine Flywheel Removal .
  32. Install the engine to the engine stand.

Installation Procedure

    Object Number: 160965 Size: SH
  1. Remove the engine from the engine stand.
  2. Install the flywheel. Refer to Engine Flywheel Installation .
  3. Install the engine to the vehicle.

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

  4. Install the upper transaxle-to-engine bolts (3,4,5) and the stud (2).

    5. Tighten
    Tighten the bolts (3,4,5) and the stud (2) to 75 N·m (55 lb ft).

  5. Remove the engine lifting device.
  6. Install the power steering pump. Refer to Power Steering Pump Replacement in Power Steering System.
  7. Install the radiator inlet hose to the engine. Refer to Radiator Inlet Hose Replacement in Engine Cooling.
  8. Install the fuel lines to the fuel rail. Refer to Metal Collar Quick Connect Fitting Service and Plastic Collar Quick Connect Fitting Service in Engine Controls - 3.1L.
  9. Install the brake booster vacuum hose to the upper intake manifold.
  10. Install the vacuum hoses to the upper intake manifold.
  11. Install the heater inlet and outlet hoses to the engine.
  12. Install the accelerator control and the cruise control cable with the bracket to the throttle body. Refer to Accelerator Control Cable Bracket Replacement in Engine Controls - 3.1L.
  13. Raise the vehicle and remove the transaxle support.
  14. Install the radiator outlet hose to the engine. Refer to Radiator Outlet Hose Replacement in Engine Cooling.
  15. Install the lower transaxle-to-engine bolt (6) and the stud (1).

    16. Tighten
    Tighten the bolt (6) and the stud (1) to 75 N·m (55 lb ft).

  16. Install the transaxle brace. Refer to Transmission Brace Replacement in Automatic Transaxle - 4T65E.
  17. Install the torque converter bolts. Refer to Flywheel to Torque Converter Bolt Replacement in Automatic Transaxle - 4T65E.
  18. Install the A/C compressor. Refer to Air Conditioning Compressor Replacement in Heating, Ventilation, and Air Conditioning.
  19. Install the starter motor. Refer to Starter Motor Replacement in Engine Electrical.
  20. Install the torque converter covers. Refer to Torque Converter Cover Replacement in Automatic Transaxle - 4T65E.

    21. Object Number: 96002 Size: SH
  21. Install the engine mount lower nuts.

    22. Tighten
    Tighten the nuts to 47 N·m (35 lb ft).

  22. Install the engine wiring harness grounds to the transaxle.
  23. Install the engine wiring harness ground nut to the transaxle stud.

    24. Tighten
    Tighten the nut to 35 N·m (26 lb ft).

  24. Install the 3-way catalytic converter pipe to the right exhaust manifold. Refer to Catalytic Converter Replacement in Engine Exhaust.
  25. Lower the vehicle.
  26. Connect the following electrical connectors:
    27. • Body wiring harness-to-engine harness
    • Ignition coil
    • Idle air control (IAC) valve
    • Throttle position (T/P) sensor
    • Evaporative emissions (EVAP) canister purge solenoid
    • Exhaust gas recirculation (EGR) valve
    • Manifold absolute pressure (MAP) sensor
    • Heated oxygen sensor (HO2S)
    • Crankshaft position (CKP) sensor
    • Camshaft position (CMP) sensor
    • Knock sensor
  27. Install the drive belt. Refer to Drive Belt Replacement .
  28. Install the engine mount struts. Refer to Engine Mount Strut Replacement .
  29. Install the hood. Refer to Hood Replacement in Body Front End.
  30. Install the air cleaner assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls - 3.1L.
  31. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  32. Fill the crankcase with engine oil. Refer to Engine Oil and Oil Filter Replacement .
  33. Fill cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  34. Check and fill the power steering system as necessary. Refer to Checking and Adding Power Steering Fluid in Power Steering System.
  35. Perform a CKP system variation learn procedure. Refer to Crankshaft Position System Variation Learn in Engine Controls - 3.1L.
  36. Inspect for leaks.