GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2003 🢒 Regal 🢒 Engine 🢒 Engine Mechanical - 3.8L 🢒 Oil Pan Replacement

Removal Procedure
  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  2. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement.
  3. Remove the air cleaner intake duct. Refer to Air Cleaner Inlet Duct Replacement for the 3.8L engine.
  4. Install the engine support fixture. Refer to Engine Support Fixture.
  5. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle

    6. Object Number: 372626 Size: SH
  6. Remove the right exhaust manifold pipe stud nuts from the catalytic converter.
  7. Drain the engine oil and remove the oil filter. Refer to Engine Oil and Oil Filter Replacement.
  8. Remove the power steering oil cooler pipe brackets from the frame.
  9. Disconnect the oil level sensor electrical connector.
  10. Remove the oil level sensor wiring harness bolt and reposition the oil level sensor wiring harness.

    11. Object Number: 50411 Size: SH
  11. Remove the engine mount lower nuts from the engine mount.
  12. Lower the vehicle.
  13. Use the engine support fixture to raise the engine.
  14. Raise the vehicle.

    15. Object Number: 97800 Size: SH
  15. Remove the left engine mount bracket bolts from the engine.

    16. Object Number: 97804 Size: SH
  16. Remove the right engine mount bracket bolts from the engine.
  17. Remove the right stabilizer link. Refer to Stabilizer Shaft Link Replacement.
  18. Remove the right ball joint from the steering knuckle. Refer to Lower Control Arm Replacement.
  19. Support the frame with jack stands.
  20. Remove the right side frame bolts and loosen the left side frame bolts 5 turns. Refer to Frame Replacement.
  21. Using the jack stands lower the frame.
  22. Remove the engine mount and the bracket from the frame.
  23. Remove the torque converter covers. Refer to Torque Converter Cover Replacement for the 4T65-E automatic transaxle.

    24. Notice: Remove the oil level sensor, located in the oil pan, before the oil pan is removed. The sensor may be damaged if the oil pan is removed first.


    Object Number: 97768 Size: SH
  24. Remove the oil level sensor.

    25. Object Number: 97771 Size: SH
  25. Remove the oil pan bolts.
  26. Remove the oil pan.

    27. Object Number: 97769 Size: SH
  27. Remove the oil pump pipe screen assembly and the oil pan gasket.
  28. Clean the following parts:
    29. • Oil pump screen mating surfaces
    • Oil pan flanges
    • Oil pan rail
    • Front cover
    • Rear main bearing cap
    • Threaded holes

Installation Procedure

    Object Number: 1341869 Size: SH

    Important: For aluminum oil pans, begin with step 4. For steel oil pans, skip steps 4 and 5.

  1. For steel oil pans, apply a continuous bead 6.35 mm (0.25 in) thick of RTV sealer GM P/N 12378521 (Canadian P/N 88901148) to the topside of the new windage tray gasket. Apply the RTV sealant directly over the sealing bead.
  2. Install the NEW windage tray gasket onto the engine.

    3. Object Number: 741054 Size: SH
  3. Apply a continuous bead 6.35 mm (0.25 in) thick of RTV sealer GM P/N 12378521 (Canadian P/N 88901148) to the bottom side of the new windage tray gasket. Apply the RTV sealant directly over the sealing bead.

    4. Object Number: 1572701 Size: SH
  4. For aluminum oil pans, apply a continuous bead 6.35 mm (0.25 in) thick of RTV sealer GM P/N 12378521 (Canadian P/N 88901148), ensuring that the sealer also completely fills the groove in the oil pan.
  5. To ensure proper sealing, apply additional sealer at the four points called out in the illustration (1).

    6. Object Number: 44775 Size: SH
  6. Install the oil pan and oil pan windage tray gasket,if applicable.

    7. Object Number: 26202 Size: SH
  7. Install the oil pump pipe screen assembly.

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

  8. Install the oil pump pipe screen bolts.

    9. Tighten
    Tighten the bolts to 15 N·m (11 lb ft).


    Object Number: 97771 Size: SH
  9. Install the oil pan.
  10. Clean the oil pan bolts and apply one drop of thread lock compound GM P/N 12345382 (Canadian P/N 10953489) or equivalent to the oil pan bolt threads.
  11. Install the oil pan bolts.

    12. Tighten
    Tighten the oil pan bolts to 14 N·m (125 lb in).


    Object Number: 97768 Size: SH
  12. Install the oil level sensor.

    13. Tighten
    Tighten the sensor to 20 N·m (15 lb ft).

  13. Install the torque converter covers. Refer to Torque Converter Cover Replacement for the 4T65-E automatic transaxle.
  14. Install the engine mount and the bracket to the frame.
  15. Using the jack stands raise the frame to the original position.
  16. Install the frame bolts. Refer to Frame Replacement.
  17. Remove the jack stands.
  18. Install the right ball joint to the steering knuckle. Refer to Lower Control Arm Replacement.
  19. Install the right stabilizer link. Refer to Stabilizer Shaft Link Replacement.

    20. Object Number: 97804 Size: SH
  20. Install the engine mount bracket to the engine.
  21. Loosely install the right engine mount bracket bolts to the engine.

    22. Object Number: 97800 Size: SH
  22. Loosely install the left engine mount bracket bolts to the engine.

    23. Tighten
    Tighten the bolts to 102 N·m (75 lb ft).

  23. Lower the vehicle.
  24. Using the engine support fixture lower the engine.
  25. Raise the vehicle.

    26. Object Number: 50411 Size: SH
  26. Install the engine mount lower nuts.

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

  27. Install the oil level sensor wiring harness and the engine wiring harness heat shield bolt to the engine.

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

  28. Connect the oil level sensor electrical connector.
  29. Install the power steering oil cooler pipe brackets to the frame.

    30. Object Number: 372626 Size: SH
  30. Install right exhaust manifold pipe stud nuts.

    31. Tighten
    Tighten the nuts to 30 N·m (22 lb ft).

  31. Install the engine oil filter.
  32. Lower the vehicle.
  33. Remove the engine support fixture.
  34. Install the right and left engine mount struts. Refer to Engine Mount Strut Replacement - Right Side and Engine Mount Strut Replacement - Left Side.
  35. Install the air cleaner intake duct. Refer to Air Cleaner Inlet Duct Replacementfor the 3.8L engine.
  36. Fill the crankcase with engine oil. Refer to Engine Oil and Oil Filter Replacement.
  37. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement.
  38. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  39. Inspect for leaks.
  40. Measure the wheel alignment. Refer to Wheel Alignment Measurement.