GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2009 🢒 LaCrosse 🢒 Engine 🢒 Engine Mechanical - 3.8L 🢒 Engine Replacement

Removal Procedure
  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  2. Remove the hood. Refer to Hood Replacement.
  3. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement.
  4. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  5. Drain the engine oil. Refer to Engine Oil and Oil Filter Replacement.
  6. Drain the cooling system. Refer to Cooling System Draining and Filling.
  7. Remove the torque converter covers. Refer to Torque Converter Cover Replacement.

    8. Object Number: 911140 Size: SH
  8. Remove the engine ground nut (5) and the engine ground wire (6) from the transaxle stud.
  9. Remove the oil level sensor harness retainer bolt.
  10. Remove the oil level harness retainer from the engine.
  11. Disconnect and reposition the electrical connectors from the following components:
    12. • Vehicle speed sensor (VSS)
    • Oil pressure sensor
    • Oil level sensor (10)
    • Knock sensors
    • Heated oxygen sensor (H02S)
  12. Remove the starter motor. Refer to Starter Motor Replacement.
  13. Remove the engine flywheel-to-torque converter bolts. Refer to Flywheel to Torque Converter Bolt Replacement.
  14. Scribe the torque converter to the flywheel for installation.
  15. Remove the transaxle brace. Refer to Transmission Brace Replacement.
  16. Remove the engine mount lower nuts.

    17. Object Number: 911163 Size: SH
  17. Remove the exhaust manifold pipe stud nuts (2) and reposition the catalytic converter from the exhaust manifold.
  18. Remove the oil filter adapter housing. Refer to Oil Filter Adapter and Bypass Valve Assembly Replacement.

    19. Object Number: 160965 Size: SH
  19. Remove the lower transaxle to the engine bolt (6) and the stud (1).
  20. Lower the vehicle while supporting the transaxle.
  21. Remove the air cleaner assembly. Refer to Air Cleaner Element Replacement.
  22. Disconnect the fuel line from the fuel rail. Refer to Metal Collar Quick Connect Fitting Service.
  23. Disconnect the fuel vapor line. Refer to Metal Collar Quick Connect Fitting Service.

    24. Object Number: 46174 Size: SH
  24. Loosen the water pump pulley bolts.
  25. Remove the drive belt. Refer to Drive Belt Replacement.
  26. Remove the water pump pulley bolts and the water pump pulley.
  27. Remove the right and the left engine mount struts. Refer to Engine Mount Strut Replacement - Right Side and Engine Mount Strut Replacement - Left Side.
  28. Remove the engine mount brackets from the radiator support. Refer to Engine Front Mount Bracket Replacement.
  29. Disconnect the positive battery cable.
  30. Remove the engine cooling fans. Refer to Engine Coolant Fan Motor Replacement.
  31. Remove the vacuum booster hose from the engine. Refer to Vacuum Brake Booster Check Valve and/or Hose Replacement.
  32. Disconnect the A/C vacuum hose from the engine.

    33. Object Number: 282122 Size: SH
  33. Remove the power steering pump bolts and pump from the engine. Lay the power steering pump aside.
  34. Disconnect the upper engine electrical connectors from the following components:
    35. • Electronic throttle control (ETC)
    • Fuel injectors
    • EVAP purge solenoid
    • Exhaust gas recirculation (EGR) valve
    • Manifold absolute pressure (MAP) sensor
    • BARO sensor, if equipped

    Note: Note the position of the engine wiring harness during removal.

  35. Remove upper engine wiring harness from the retaining clips and reposition the engine wiring harness for engine removal.
  36. Remove the radiator inlet hose from the engine. Refer to Radiator Inlet Hose Replacement.
  37. Remove the radiator outlet hose from the engine. Refer to Radiator Outlet Hose Replacement.
  38. Remove the heater hoses from the drive belt tensioner. Refer to Heater Inlet Hose Replacement and to Heater Outlet Hose Replacement.
  39. Remove the A/C compressor from the engine. Refer to Air Conditioning Compressor Replacement. DO NOT discharge the A/C system. Secure the compressor to the frame.
  40. Install the engine lifting device.

    41. Object Number: 160965 Size: SH
  41. Remove the upper transaxle to the engine bolts (2, 3, 4, 5).
  42. With the aid of an assistant, remove the engine from the vehicle.
  43. Remove the flywheel. Refer to Engine Flywheel Replacement.
  44. Install the engine to the engine stand.

Installation Procedure
  1. Remove the engine from the engine stand.
  2. Install the flywheel. Refer to Engine Flywheel Replacement.
  3. With the aid of an assistant, install the engine to the vehicle.

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


    Object Number: 160965 Size: SH
  4. Install the upper transaxle to the engine bolts (2, 3, 4, 5).

    5. Tighten
    Tighten the bolts to 75 N·m (55 lb ft).

  5. Remove the engine lifting device.
  6. Install the A/C compressor to the engine. Refer to Air Conditioning Compressor Replacement.
  7. Install the heater hoses to the drive belt tensioner. Refer to Heater Inlet Hose Replacement and Heater Outlet Hose Replacement.
  8. Install the radiator outlet hose to the engine. Refer to Radiator Outlet Hose Replacement.
  9. Install the radiator inlet hose to the engine. Refer to Radiator Inlet Hose Replacement.
  10. Reposition and install the engine wiring harness to the engine as noted during removal.
  11. Connect the upper engine electrical connectors to the following components:
    12. • BARO sensor, if equipped
    • MAP sensor
    • EGR valve
    • EVAP purge solenoid
    • Fuel injectors
    • Electronic throttle control (ETC)
  12. Install the upper engine wiring harness to the retaining clips.

    13. Object Number: 282122 Size: SH
  13. Install the power steering pump to the engine.
  14. Install the power steering pump bolts.

    15. Tighten
    Tighten the bolts to 34 N·m (25 lb ft).

  15. Connect the A/C vacuum hose to the engine.
  16. Install the vacuum booster hose to the engine. Refer to Vacuum Brake Booster Check Valve and/or Hose Replacement.
  17. Install the engine cooling fans. Refer to Engine Coolant Fan Motor Replacement.
  18. Connect the positive battery cable.

    19. Tighten
    Tighten the cable terminal bolt to 15 N·m (11 lb ft).

  19. Install the engine mount brackets to the upper radiator support. Refer to Engine Front Mount Bracket Replacement.
  20. Install the engine mount struts to the engine mount strut brackets. Refer to Engine Mount Strut Replacement - Right Side and Engine Mount Strut Replacement - Left Side.

    21. Object Number: 46174 Size: SH
  21. Install the water pump pulley.
  22. Install the water pump pulley bolts.

    23. Tighten
    Tighten the pulley bolts to 13 N·m (116 lb in).

  23. Install the drive belt. Refer to Drive Belt Replacement.
  24. Connect the fuel vapor line. Refer to Metal Collar Quick Connect Fitting Service.
  25. Connect the fuel line to the fuel rail. Refer to Metal Collar Quick Connect Fitting Service.
  26. Install the air cleaner assembly. Refer to Air Cleaner Element Replacement.
  27. Raise the vehicle and remove the transaxle support.

    28. Object Number: 160965 Size: SH
  28. Install the lower transaxle to the engine bolt (6) and the stud (1).

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

  29. Install the oil filter adapter housing. Refer to Oil Filter Adapter and Bypass Valve Assembly Replacement.

    30. Object Number: 911163 Size: SH
  30. Install a new gasket (1) and the catalytic converter (3) to the right exhaust manifold.
  31. Install the exhaust manifold pipe stud nuts (2).

    32. Tighten
    Tighten the nuts to 35 N·m (26 lb ft).

  32. Install the engine mount lower nuts.

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

  33. Install the transaxle brace. Refer to Transmission Brace Replacement.
  34. Install the engine flywheel-to-torque converter bolts. Refer to Flywheel to Torque Converter Bolt Replacement.
  35. Install the starter motor. Refer to Starter Motor Replacement.

    36. Object Number: 911140 Size: SH
  36. Reposition and connect the electrical connectors to the following components:
    37. • HO2S
    • Knock sensors
    • Oil level sensor (10)
    • Oil pressure sensor
    • VSS
  37. Install the oil level sensor harness retainer to the engine.
  38. Install the oil level sensor harness retainer bolt.

    39. Tighten
    Tighten the bolt to 10 N·m (89 lb in).

  39. Install the engine ground wire (6) and the engine ground wire nut (5) to the transaxle stud.

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

  40. Install the torque converter covers. Refer to Torque Converter Cover Replacement.
  41. Lower the vehicle.
  42. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement.
  43. Install the hood. Refer to Hood Replacement.
  44. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  45. Fill the crankcase with engine oil. Refer to Engine Oil and Oil Filter Replacement.
  46. Fill the cooling system. Refer to Cooling System Draining and Filling.
  47. Inspect for leaks.
  48. Perform the CKP system variation learn procedure. Refer to Crankshaft Position System Variation Learn.