GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1997 🢒 Century 🢒 Engine 🢒 Engine Mechanical - 3.1L and 3.4L 🢒 Engine Block Cleaning and Inspection

    Important: Caustic cleaning solution destroys the bearing material. All bearings must be replaced after cleaning with a caustic solution. Do not clean bearing material or aluminum parts with caustic solutions.

  1. Clean the following parts:
    2. • The sealing material from the mating surfaces
    • The oil passages
    • All the blind holes

    Object Number: 58490 Size: SH
  2. Use the following procedure in order to check the surface for flatness:
    3. • Use a straight edge and a feeler gauge.
    • Minor irregularities may be carefully machined.
    • If more than 0.25 mm (0.010 in) the block must be replaced.
  3. Clean the oil pan rail and timing cover attaching area for nicks. Minor irregularities may be cleaned up with a flat mill file.
  4. Clean the head bolt tapped holes.
  5. Clean the transaxle case mating surface.
  6. Measure the crankshaft flange run-out. With the crankshaft installed, place the dial indicator stem just outside the flywheel mounting bolt holes. Set the indicator to 0. Rotate the crankshaft and record the readings. If the readings are not within limits, the crankshaft must be replaced.

    7. Notice: A broken flywheel may result if the transmission case mating surface is not flat.


    Object Number: 61327 Size: SH
  7. Measure the cylinder block flange surface run-out at six mounting hole bosses.

    8. Object Number: 61321 Size: SH
  8. Hold the gauge plate flat against the crankshaft flange.
  9. Place the dial indicator stem on the transaxle mounting bolt hole boss and set the indicator to 0.
  10. Record the readings from the remaining transaxle mounting bolt hole bosses. Measurements should not vary more than 0.25 mm (0.010 in).
  11. If the readings vary more than 0.25 mm (0.010 in), recheck the crankshaft flange run-out. Replace the crankshaft if the run-out is excessive.
  12. Inspect the threaded holes. If necessary, clean with a tap or drill out and install the thread inserts.

    13. Important: The following inspections as well as reconditioning, if necessary, must be carried out with the main bearing caps installed and tightened to specification. Ensure that the main bearing caps are installed correctly, with the arrows pointing toward the front of the engine.

  13. Inspect the camshaft and the crankshaft bearing bores. Use the J 8087 , measure the bore diameter and out-of-round.

    14. Object Number: 9374 Size: SH
  14. Inspect the cylinder bore. Use theJ 8087 in order to measure for wear, taper, out-of-round and ridging.

    15. Object Number: 4973 Size: SH
  15. If the bore is worn out of specifications, it may be rebored, honed and fitted with oversize pistons. The smallest available oversize should be selected.
  16. Leave sufficient material in order to allow finish honing in conjunction with fitting the piston.
  17. If the bore is glazed but otherwise serviceable, break the glaze lightly with a hone and replace the piston rings.
  18. Move the hone slowly up and down in order to produce a crosshatch pattern. Clean the bore thoroughly with soap and water. Dry and rub in clean engine oil, then measure.