BMW 318/325/M3/525/535/M5 1989-1993 Repair Information

Crankshaft and Main Bearings



  1. Drain the engine oil and remove the engine from the car. Mount the engine on a workstand in a suitable working area. Invert the engine, so the oil pan is facing up.

The epa warns that prolonged contact with used engine oil may cause a number of skin disorders, including cancer! You should make every effort to minimize your exposure to used engine oil. Protective gloves should be worn when changing the oil. Wash your hands and any other exposed skin areas as soon as possible after exposure to used engine oil. Soap and water, or waterless hand cleaner should be used.

  1. Remove the engine front (timing) cover.
  3. Remove the timing chain/belt and gears.
  5. Remove the oil pan.
  7. Remove the oil pump.
  9. Stamp the cylinder number on the machined surfaces of the bolt bosses of the connecting rods and caps for identification when reinstalling. If the pistons are to be removed eventually from the connecting rod, mark the cylinder number on the pistons with silver paint or felt-tip pen for proper cylinder identification and cap-to-rod location.
  11. Remove the connecting rod caps. Install lengths of rubber hose on each of the connecting rod bolts, to protect the crank journals when the crank is removed.
  13. Mark the main bearings caps with a number punch or punch so that they can be reinstalled in their original positions.