GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2003 🢒 LeSabre 🢒 Engine 🢒 Engine Mechanical - 3.8L 🢒 Oil Pump Cover and Gear Set Replacement

Removal Procedure
  1. Remove the engine front cover. Refer to Engine Front Cover Replacement .
  2. Remove the oil filter adapter.
  3. Remove the pressure regulator valve and the spring. Refer to Oil Filter Adapter and Bypass Valve Assembly Replacement .

    4. Object Number: 153600 Size: SH
  4. Remove the oil pump cover attaching screws.
  5. Remove the oil pump cover.
  6. Remove the oil pump gear set.
  7. Clean and inspect the oil pump gear set and housing. Refer to Oil Pump Cleaning and Inspection in the Engine Mechanical - 3.8L Unit Repair.

Installation Procedure

    Object Number: 153600 Size: SH
  1. Lubricate the oil pump gears with petroleum jelly.
  2. Install the oil pump gear set.
  3. Pack the oil pump gears with petroleum jelly.
  4. Install the oil pump cover.

    5. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  5. Install the oil pump cover screws.

    6. Tighten
    Tighten the oil pump cover screws to 11 N·m (98 lb in).

  6. Install the oil filter adapter with a new gasket. Install the pressure regulator valve and the spring. Refer to Oil Filter Adapter and Bypass Valve Assembly Replacement .
  7. Install the engine front cover. Refer to Engine Front Cover Replacement .

    8. Notice: Do not run the engine until the oil pressure is tested. Running the engine without measurable oil pressure will cause extensive damage.

    Notice: Stop the engine and remove the oil pan if the oil pressure does not build up immediately. Check the oil pump pipe and the screen for a clogged screen, damaged pipe, or a damaged gasket. Running the engine without measurable oil pressure will cause extensive damage.

  8. Inspect the oil pressure.
  9. Inspect for the proper fluid levels.
  10. Inspect for leaks.