GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Metro 🢒 Engine 🢒 Engine Mechanical - 1.0L 🢒 Piston Selection

Important: Measurements of all components should be taken with the components at normal room temperature.

For proper piston fit, the engine block cylinder bores must not have excessive wear or taper.

A used piston and pin set may be reinstalled if, after cleaning and inspection, they are within specifications.

  1. Inspect the engine block cylinder bore.

    2. Refer to Engine Block Cleaning and Inspection in Engine Mechanical.

  2. Inspect the piston and the piston pin.

    3. Refer to Piston, Connecting Rod, and Bearing Cleaning and Inspection in Engine Mechanical.


    Object Number: 4972 Size: SH
  3. Use a bore gauge and measure the cylinder bore diameter. Measure at a point 64 mm (2.5 in) from the top of the cylinder bore.

    4. Object Number: 4974 Size: SH
  4. Measure the bore gauge with a micrometer and record the reading.

    5. Object Number: 236210 Size: SH
  5. With a micrometer or caliper at a right angle to the piston, measure the piston 25 mm (1 in) from the top of the piston.
  6. Subtract the piston diameter from the cylinder bore diameter in order to determine piston-to-bore clearance.
  7. For proper piston-to-bore clearance.

    8. Refer to Engine Mechanical Specifications in Engine Mechanical.

  8. If the proper clearance cannot be obtained, select another piston and measure for the clearances.
  9. If the proper fit cannot be obtained, hone the cylinder bore or replace the cylinder block.
  10. When the piston-to-cylinder bore clearance is within specifications, mark the top of the piston using a permanent marker for installation to the proper cylinder.