LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2004 >> CTS Base, 3.2 N >> Repair and Diagnosis >> Engine Mechanical >> Engine Mechanical - 3.2L >> Repair Instructions >> Off-Vehicle Repair Instructions >> Piston, Connecting Rod, and Bearings Cleaning and Inspection

Piston, Connecting Rod, and Bearings Cleaning and Inspection

  1. Use cleaning solvent to clean the connecting rod.
    2. CAUTION: Refer to Safety Glasses Caution in Cautions and Notices.
    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. Fig 1: Cleaning The Piston Ring Grooves With Suitable Ring Groove Cleaning Tool
    GM4977Courtesy of GENERAL MOTORS CORP.
  5. Use a groove cleaner to clean the piston ring.
  6. Inspect the connecting rod for the following conditions:
    • 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:
    • 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. Fig 2: Measuring Piston Ring End Gap
    GM4968Courtesy of GENERAL MOTORS CORP.
  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. Fig 3: Measuring Piston Ring Side Clearance
    GM22934Courtesy of GENERAL MOTORS CORP.
  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.
scientia non olet · About LEMON Manuals