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Technical Article
What Are the Signs of FIVA Valve Failure?
Common signs of FIVA valve failure on electronically controlled two-stroke engines include power loss on a single cylinder, fuel-injection or exhaust-valve timing errors, control-system alarms and error codes, unstable or erratic running, and hydraulic (servo) oil leakage. Because the FIVA valve controls both injection and exhaust-valve actuation, a fault usually shows as abnormal combustion on the affected unit.
Common signs of FIVA valve failure on electronically controlled two-stroke engines include power loss on a single cylinder, fuel-injection or exhaust-valve timing errors, control-system alarms and error codes, unstable or erratic running, and hydraulic (servo) oil leakage. Because the FIVA valve controls both injection and exhaust-valve actuation, a fault usually shows as abnormal combustion on the affected unit.
What is a FIVA valve?
FIVA stands for Fuel Injection and Valve Actuation. On electronically controlled two-stroke engines (such as MAN B&W ME engines) the FIVA valve is a hydraulically actuated, electronically controlled proportional valve that governs both fuel injection timing and exhaust-valve operation for its cylinder unit.
What are the common symptoms of FIVA valve failure?
- Power loss or abnormal combustion on one cylinder unit
- Fuel injection or exhaust-valve timing deviations
- Control-system (ECU) alarms, feedback faults, or error codes
- Unstable, hunting, or erratic engine running
- Servo/hydraulic oil leakage around the valve
- Deviations in exhaust gas temperature on the affected unit
What causes FIVA valves to fail?
- Contaminated or degraded servo/hydraulic oil
- Wear of internal spool and sleeve components
- Electrical or feedback-sensor faults
- Sticking due to deposits or poor oil condition
When should a FIVA valve be serviced or replaced?
A FIVA valve should be inspected when timing faults, repeated alarms, or unit-specific performance deviations appear, and overhauled or exchanged when internal wear or feedback faults are confirmed. Controlled workshop testing verifies performance before return to service. Always follow the engine maker's guidance and maintain clean servo oil.
Written by the Dieselmech Group engineering team. For advice on a specific engine or fault, contact our marine engineers.
