Piston Selection

NOTE: The cylinder bore must be within the specifications for taper and out-of-round before fitting a piston.

Select a piston size based on the cylinder bore.

Fig 1: Identifying Cylinder Bore Out-Of-Round
Courtesy of FORD MOTOR CO.
Choose the piston with the correct paint color or specific size grade.
- Refer to SPECIFICATIONS (2.5L), SPECIFICATIONS (Hybrid), SPECIFICATIONS (3.0L) and SPECIFICATIONS (3.5L) for the procedure.
NOTE: For precision fit, new pistons are divided into 3 categories within each size range based on their relative position within the range. A paint spot or specific size grade on a new piston indicates the position within the size range.

Fig 2: Locating Correct Paint Color Or Specific Size Grade
Courtesy of FORD MOTOR CO.