GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 8001 Dial Indicator Set
    • J 8087 Cylinder Bore Gage

    Object Number: 537092  Size: SH
  1. Clean the sealing material from the gasket mating surfaces.
  2. Boil the engine block in caustic solution.
  3. Flush the engine block with clean water or steam.
  4. Clean the oil passages.
  5. Clean the blind holes.
  6. Spray the cylinder bores and the machined surfaces with engine oil.
  7. Inspect the threaded holes.
  8. Clean the holes with a tap. Drill out the holes and install thread inserts, as needed.

  9. Object Number: 5272  Size: SH
  10. Use a straight edge and a feeler gauge in order to test the deck surface for flatness. Replace the block if it is outside of the specification limit.
  11. Inspect the oil pan rail for nicks.
  12. Inspect the front cover attaching area for nicks. Use a flat mill file in order to remove any nicks.

  13. Object Number: 38648  Size: SH
  14. Inspect the mating surfaces of the transmission case.
  15. Notice: A broken flywheel may result if the transmission case mating surface is not flat.

  16. Use the following procedure in order to measure the engine block flange runout at the 6 mounting bolt hole bosses:
  17. 13.1. Temporarily install the crankshaft. Measure the crankshaft flange runout.
    13.2. Hold the J 8001 gage plate flat against the crankshaft flange.
    13.3. Place the dial indicator stem on the transmission mounting bolt hole boss. Set the indicator to 0.
    13.4. Record the readings obtained from all of the bolt hole bosses. The measurements should not vary more than 0.25 mm (0.010 in).
    13.5. Retest the crankshaft flange runout if the readings vary more than 0.25 mm (0.010 in). If the crankshaft flange runout is not within the specification, replace the engine block.

    Object Number: 38663  Size: SH

    Important: Perform the following inspections, and reconditioning if necessary, with the crankshaft main bearing caps installed and tightened to specification.

  18. Inspect the crankshaft main bearing bores. Use the J 8087 in order to measure the bearing bore concentricity and alignment at the following locations:
  19. • The camshaft
    • The crankshaft
  20. Replace the engine block if the bores are out of specification.

  21. Object Number: 38662  Size: SH
  22. Use the J 8087 in order to inspect the cylinder bores. Inspect the bores for the following conditions:
  23. • Wear
    • Taper
    • Runout
    • Ridging

    Important: If the bore is worn beyond the limits, refit the bore with 0.5 mm (0.02 in) oversized pistons.

  24. Leave sufficient material in order to allow honing when fitting the piston.

Special Tools

    • J-8001 Dial Indicator Set
    • J-8087 Cylinder Bore Gage

For equivalent regional tools, refer to Special Tools


    Object Number: 537092  Size: SH
  1. Clean the sealing material from the gasket mating surfaces.
  2. Boil the engine block in caustic solution.
  3. Flush the engine block with clean water or steam.
  4. Clean the oil passages.
  5. Clean the blind holes.
  6. Spray the cylinder bores and the machined surfaces with engine oil.
  7. Inspect the threaded holes.
  8. Clean the holes with a tap. Drill out the holes and install thread inserts, as needed.

  9. Object Number: 5272  Size: SH
  10. Use a straight edge and a feeler gauge in order to test the deck surface for flatness. Replace the block if it is outside of the specification limit.
  11. Inspect the oil pan rail for nicks.
  12. Inspect the front cover attaching area for nicks. Use a flat mill file in order to remove any nicks.

  13. Object Number: 38648  Size: SH
  14. Inspect the mating surfaces of the transmission case.
  15. Caution: A broken flywheel may result if the transmission case mating surface is not flat.

  16. Use the following procedure in order to measure the engine block flange runout at the 6 mounting bolt hole bosses:
  17. 13.1. Temporarily install the crankshaft. Measure the crankshaft flange runout.
    13.2. Hold the J-8001 Dial Indicator Set gage plate flat against the crankshaft flange.
    13.3. Place the dial indicator stem on the transmission mounting bolt hole boss. Set the indicator to 0.
    13.4. Record the readings obtained from all of the bolt hole bosses. The measurements should not vary more than 0.25 mm (0.010 in).
    13.5. Retest the crankshaft flange runout if the readings vary more than 0.25 mm (0.010 in). If the crankshaft flange runout is not within the specification, replace the engine block.

    Object Number: 38663  Size: SH

    Note: Perform the following inspections, and reconditioning if necessary, with the crankshaft main bearing caps installed and tightened to specification.

  18. Inspect the crankshaft main bearing bores. Use the J-8087 Cylinder Bore Gage in order to measure the bearing bore concentricity and alignment at the following locations:
  19. • The camshaft
    • The crankshaft
  20. Replace the engine block if the bores are out of specification.

  21. Object Number: 38662  Size: SH
  22. Use the J-8087 Gage in order to inspect the cylinder bores. Inspect the bores for the following conditions:
  23. • Wear
    • Taper
    • Runout
    • Ridging

    Note: If the bore is worn beyond the limits, refit the bore with 0.5 mm (0.02 in) oversized pistons.

  24. Leave sufficient material in order to allow honing when fitting the piston.