Operation CHARM: Car repair manuals for everyone.

Piston, Engine

Piston and ring specifications

Check the piston diameter -D- at the prescribed measuring point on the piston shank using an outside micrometer.
Measuring point from lower edge of shank dimension X = 15 mm.





Checking the piston shank diameter

The maximum wear allowed at the specified measuring point is 100 microns (= 0.1 mm). If this measurement is exceeded, the piston must be replaced. The reference measurements are listed in the table below.





Piston rings and piston ring groove:

Piston rings:
- Check piston rings for signs of wear.
- Piston-ring end clearance is measured in the cylinder.








Piston pin:
- Check for signs of wear and tear.
- Dimensional check using outside micrometer: diameter = 22.0 - 0.02 mm.