Chief Engineer
A ship's main engine is the beating heart of the vessel. Don't wait for a catastrophic failure at sea. Learn to identify the subtle warning signs in exhaust temperature, lube oil consumption, and vibration analysis that clearly indicate a major overhaul is due before it becomes an emergency repair.
1. Abnormal Exhaust Gas Temperatures (EGT)
High or drastically fluctuating exhaust temperatures across different cylinders is a massive red flag. Consistently high temperatures indicate poor combustion, often caused by worn fuel injectors, incorrect timing, or insufficient scavenging air due to a fouled turbocharger. If EGT deviation between cylinders exceeds manufacturer allowances, it's time to open the engine.
2. Dark, Thick Exhaust Smoke
While some smoke during startup or rapid load changes is normal, continuous black or dense gray smoke under steady load implies unburnt fuel. This could be due to worn piston rings failing to provide proper compression, or badly carbonized fuel injector nozzles.
3. Spikes in Lube Oil Consumption
If you find yourself constantly topping up the sump tank, the lubricating oil is bypassing the scraper rings and entering the combustion chamber. This not only wastes expensive oil but creates heavy carbon deposits on the piston crown and exhaust valves.
4. Contaminated Engine Oil
Regular oil analysis testing is mandatory. If lab results show high levels of metallic shavings (iron, copper, or lead), it indicates severe bearing or cylinder liner wear. Water or coolant in the oil (creating a milky appearance) points to a blown cylinder head gasket or cracked liner.
5. Loss of Engine Power and RPM
If the engine is struggling to achieve its rated RPM under normal sea conditions, or if the vessel is inexplicably losing speed, the engine is suffering from a severe lack of compression or fuel starvation. Worn liners and sticking piston rings are usually the culprits.
6. Excessive Crankcase Pressure (Blow-by)
High pressure inside the crankcase occurs when combustion gases blow past the piston rings. This is a definitive sign that the cylinder sealing is severely compromised. In extreme cases, explosive crankcase mists can form.
7. Unusual Knocking or Mechanical Vibrations
A sharp metallic knocking sound often signifies "piston slap" (due to extreme liner wear) or critically worn big-end/crankpin main bearings. Continuing to run an engine with severe bearing knock will inevitably result in a snapped crankshaft.
8. Difficult Engine Starting
If the engine requires an unusually long crank time utilizing the starting air compressors, or fails to catch entirely, it is failing to build enough compression heat to self-ignite the injected fuel.
9. Frequent Engine Alarms and Trips
A modern engine control system will warn you. If you are experiencing frequent low lube oil pressure alarms, high jacket water temperature alarms, or crankcase oil mist detector trips, the engine is begging for maintenance.
10. Exceeding Recommended Running Hours
Finally, regardless of how well the engine seems to be running, if you have bypassed the manufacturer's recommended service intervals (e.g., 20,000 hours for a major overhaul), you are operating on borrowed time. Metal fatigue is invisible until the moment it snaps.
If your vessel is exhibiting any combination of these signs, contact the engineering experts at Leon International immediately to schedule a dry-dock or voyage repair overhaul.
