17 ENGINE
17.4.18 Checking/measuring the piston
200
e-'
+
400995-10
310043-10
- Use the special tool to measure clearance
f)
of the piston
rings in the piston ring groove.
Guideline
Piston ring - groove clear
ance
:S 0.08 mm (:S 0.0031 in)
I Feeler gauge (59029041100) (
IUI
p. 299)
If clearance
f)
larger than the specified value:
- Change the piston and piston rings.
- Check/measure the cylinder. (
IUI
p. 199)
- Check the piston bearing surface for damage.
If the piston bearing surface is damaged:
- Replace the piston and, if necessary, the cylinder.
- Check that the piston rings move easily in the piston ring
grooves.
If the piston ring is stiff:
- Clean the piston ring groove.
Tip
An old piston ring can be used to clean the
piston ring groove.
- Check the piston rings for damage.
If the piston ring is damaged:
- Change the piston ring.
•
Info
I
Mount the piston ring with the marking facing
upward.
- Check the piston pins for discoloration or signs of wear.
If the piston pin shows severe discoloration/signs of wear:
- Change the piston pin.
- Place the piston pin in the connecting rod and check the
seating for play.
If the piston pin seating has excessive play:
- Change the connecting rod and piston pin.
- Place the piston pin in the piston and check the seating for
play.
If the piston pin seating has excessive play:
- Replace the piston and, if necessary, the cylinder and
piston pin.
