Black Spots -Cylinder liner with black lacquer and cold corrosion

Wartsila Guide for condition of relevant piston-running components
(liner, pistons and piston rings) Version 2,1 June 2014.

6.2 To be monitored
6.2.2 Liner

Condition: Cylinder liner with quite some cold corrosion and some black lacquer
Acceptance: To be monitored
Action: Check correct cylinder oil feed rate setting in line with technical bulletins (TB) RT-161, RT-138
and recommendations as given in TB RTA-79.2 resp. RT-flex-08.2. Check residual BN in piston
underside drain oil in line with TB RT-138.

Condition: Cylinder liner with black lacquer and cold corrosion
Acceptance: To be monitored
Action: Check correct cylinder oil feed rate setting in line with technical bulletins (TB) RT-161, RT-138
and recommendations as given in TB RTA-79.2 resp. RT-flex-08.2. Check residual BN in piston
underside drain oil in line with TB RT-138.
The formation and extent of this lacquer formation depends mainly on engine load, sulphur content in
fuel oils (~2.7% or higher), 12 set cylinder oil feed rate and air humidity.