2002 Ford ZX2 StandardFACTORY OEM SERVICE PROCEDURE

Piston Selection

WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: The cylinder bore must be within the specifications for taper and out-of-round before fitting a piston.
  1. Select a piston size based on the cylinder bore.
    Fig 1: Identifying Cylinder Bore Measuring Directions
    G03905260Courtesy of FORD MOTOR CO.
  2. NOTE: For precision fit, new pistons are divided into 3 categories (grade sizes). A paint spot on the new pistons indicates the grade size. Choose the piston with the correct paint color after measuring the cylinder bore diameter.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.