Why Is My Marine Diesel Engine Losing Power? #
A marine diesel engine that suddenly loses power, struggles to accelerate or cannot reach its normal RPM can have problems involving several different systems.
The first important question is when the power loss occurs.
An engine that performs poorly all the time may have a different problem from one that runs perfectly at the dock but loses RPM once the vessel is underway.
Common Causes of Marine Diesel Power Loss #
Possible causes include:
- Restricted fuel filters
- Contaminated diesel fuel
- Inadequate fuel supply
- Weak lift pump
- High-pressure fuel-system problems
- Injector problems
- Restricted air intake
- Turbocharger problems
- Exhaust restrictions
- Cooling-system problems
- Electronic engine-control faults
- Excessive vessel or propeller load
- Internal engine wear
Several of these problems can create nearly identical symptoms, which is why accurate diagnostics are important.
Why Does the Engine Lose Power Under Load? #
Fuel, air and cooling requirements increase as engine load increases.
A partially restricted fuel filter may provide enough fuel for the engine to idle normally but become unable to keep up once fuel demand rises.
A restricted heat exchanger or weak raw-water pump can behave similarly. Cooling may appear normal at idle but become inadequate at cruising RPM.
Turbocharger problems may also become more noticeable as engine load increases.
This is why some marine diesel performance problems cannot be accurately diagnosed while the vessel remains tied to the dock.
Sea-Trial Diagnostics #
When necessary, a sea trial allows the engine to be evaluated under real operating conditions.
During a sea trial, technicians may evaluate:
- Engine RPM
- Engine temperature
- Acceleration
- Turbocharger response
- Exhaust smoke
- Engine alarms
- Vibration
- Performance under load
Reproducing the symptom can provide valuable information about what is preventing the engine from producing normal power.
Learn more about Marine Diesel Engine Repair & Diagnostics.
Need Help With Marine Diesel Power Loss? #
If your yacht or boat is losing power, struggling to reach RPM or performing differently than normal, All Tech Diesel can help determine why.
We provide mobile marine diesel diagnostics throughout Marco Island, Naples and Southwest Florida.
