Findings
Measure
Burn mark
Burn marks are caused by a disturbance in the liner / ring tribo system. Usually
they run over the whole ring-travel area (TDC/BDC), starting at the first TDC-ring
and becoming more visible from the second TDC-ring onwards and less pro-
nounced from TDC-ring 1. The honing pattern is usually no longer visible and dis-
plays a clearly defined (straight) edge to the undisturbed surface. The damaged
surface is usually discolored. The circumferential length varies.
Liners with heat discoloration starting in the TDC-ring 1 have to be replaced.
Seizure marks, scuffing Seizure marks are of irregular circumferential length and depth. Can be caused by
either the piston skirt or the piston crown. Material deposits on the liner (smears)
show heavy discoloration and scoring.
Replace liner.
Evaluation of findings and further measures
The findings in the start phase of oxidation discoloration and burn marks are similar. A thorough investigation
and compliance with the above evaluation criteria allow an unambiguous evaluation. To avoid unnecessary
disassembly work, it is recommended that another inspection be carried out after further operation of the
engine.
80 | Cylinder Liner | MS150049/04E 2017-04
TIM-ID: 0000003285 - 004
