Even well‑maintained marine diesel genset may meet faults under complex sea working conditions. Understanding typical onboard genset failures helps crew do fast preliminary judgment, reduce downtime risk during navigation.

1. Generator hard to start or cannot crank Main reasons: corroded / aging starting battery, loose wiring terminals; fuel contaminated by seawater ingress; blocked fuel filter; low lube oil pressure. Troubleshooting: inspect battery voltage & connection; check fuel quality and filter blockage; verify oil level.
2. Engine runs but no power output / unstable voltage The high‑frequency fault comes from damaged AVR (Automatic Voltage Regulator), worn carbon brush, corroded excitation circuit, or overload of onboard electric appliances. Unstable voltage will bring great damage to precise navigation and communication equipment. Troubleshooting: check circuit breaker status; inspect AVR unit and carbon‑brush wear status; reduce simultaneous high‑power load.
3. Over‑heating alarm and automatic shutdown It is the most frequent marine genset fault. Main triggers: seawater strainer blocked by seaweed and shell; damaged seawater pump impeller; fouled heat‑exchanger; poor engine‑room ventilation. Important note: do NOT shut down hot unit abruptly. Run idle speed for several minutes for gradual cooling before stop, to avoid thermal‑shock damage to engine components.
4. Excessive vibration and abnormal noise Caused by damaged shock‑absorbing mounting cushion, coupling misalignment, worn internal bearing, or pipeline loose under wave vibration. Timely inspection is required, or continuous vibration will crack pipelines and wiring.

Notice: Troubleshooting above is for on‑board preliminary check. For serious mechanical or electrical damage, please contact professional marine service engineers.

Our marine gensets are equipped with intelligent alarm controller, which can display fault code for fast locating problem. We offer global technical support for marine generator projects.