While in the past the selection and dosage of the lubricant was based solely on fuel sulphur content it is now necessary to take into account a number of new factors.To comply with Tier II NOx regulations and the latest Energy Efficiency Design Index (EEDI) guidelines engine manufacturers have changed their engine design. As a result cold corrosion in these engines is more likely to occur due to liner operation temperatures below the acid dew point. To enable effective slow speed operation older engines are modified to optimize “fuel consumption”. These engines now suffer similar problems due to operation at lower temperatures.
Monitoring of the iron content in the cylinder drain oil and the launching of remedial actions in due time can help to avoid cold corrosion and unnecessary abrasive wear in the cylinder liner.