GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2003 🢒 CTS - RHD 🢒 Preface 🢒 Cautions and Notices 🢒 Piston, Connecting Rod, and Bearing Cleaning and Inspection
  1. Use cleaning solvent to clean the connecting rod.

    2. Caution: Refer to Safety Glasses Caution in the Preface section.

    Important: DO NOT use any mechanical means to clean the rod to cap mating surfaces. These surfaces are "fractured" after machining and any alteration to these surfaces could lead to engine failure.

  2. Use compressed air to dry the connecting rod.

    3. Important:  DO NOT wire brush the piston skirt or the ring groove area.

  3. Use cleaning solvent to clean the pistons if reusing the pistons.
  4. Use cleaning solvent to clean the piston pins if reusing the piston pins. New pistons contain new piston pins.

    5. Object Number: 4977 Size: SH
  5. Use a groove cleaner to clean the piston ring.
  6. Inspect the connecting rod for the following conditions:
    7. • Twists
    • Replace if damage is evident.
    • Nicks
    • Replace if damage is evident.
    • Cracks
    • Replace if damage is evident.
  7. Inspect the pistons for the following conditions, replace the piston if any of the below is evident:
    8. • Cracked skirts
    • Cracked piston pin bosses
    • Cracked ring groove lands
    • Nicks that may cause binding
    • Burrs that may cause binding
    • Warped ring groove lands
    • Worn ring groove lands
    • Eroded areas on top of the piston
    • Worn piston pin bores
  8. Use a micrometer and use an inside micrometer to measure the piston pin bore-to-piston pin clearance.
  9. The maximum clearance is 0.003 - 0.008 mm (0.0001 - 0.0003 in).
  10. Replace the piston and replace the pin if the pin bore-to-piston pin clearance is beyond the proper specification.

    11. Object Number: 4968 Size: SH
  11. Measure the piston ring end gap clearance in the bore. Perform only after the cylinder has been honed.
  12. The 1st and the 2nd compression ring gap specification is 0.30 - 0.50 mm (0.0118 - 0.0196 in).
  13. Replace the piston rings if the end gap clearance is not within the proper specification.
  14. The oil control ring end gap specification is 0.40 - 1.40 mm (0.0157 - 0.0551 in).
  15. Replace the piston rings if the end gap clearance is not within the proper specification.

    16. Object Number: 22934 Size: SH
  16. Measure the piston ring groove clearance.
  17. The 1st and the 2nd compression ring groove clearance specification is 0.02 - 0.04 mm (0.0008 - 0.0015 in).
  18. Replace the piston if the ring groove clearance is not within the proper specification.
  19. The oil control ring groove clearance specification is 0.01 - 0.03 mm (0.0004 - 0.0012 in).
  20. Replace the piston if the ring groove clearance is not within the proper specification.