Repair
Marine engine diagnostics that find the cause, not just the code
Diagnostics is the step where the symptom gets traced to an actual failed component. I read the engine management computer, take live readings under load, and put a borescope inside the engine where the picture is unclear. That is cheaper than replacing parts in sequence until the fault disappears.
A fault code is a symptom, not a diagnosis
A code tells you which sensor is unhappy. It does not tell you whether the sensor failed, the wiring corroded, or the thing the sensor watches is genuinely wrong. Guessing from the code alone is how owners end up paying for three parts to fix one problem.
What is included
- Engine management computer readout and stored fault history
- Live sensor data captured under load, not at idle
- Video borescope inspection of cylinders and internal passages
- Compression and leak down testing where warranted
- Exhaust temperature, boost and fuel pressure readings
- Charging and starting circuit testing
- Written explanation of the cause and the options
How it works
Capture the fault
Stored codes, freeze frame data and the history come off the engine management computer first.
Verify under load
Most marine faults only show themselves with the engine working. Readings get taken running, not idling at the dock.
Look inside
Where readings are ambiguous the borescope goes in, so the decision to open an engine is made on a picture rather than a hunch.
Marine diesel diagnostics at Jon Diesel Marine combine engine management fault history, live sensor readings captured under load, and video borescope inspection, so that internal condition is confirmed visually before an engine is opened.
Related repair work
Diesel Repair
Engine, transmission and generator service on marine diesels, from routine maintenance through a complete repower.
Engine Repower
Replacing tired engines with new power, including the mounts, controls, exhaust and propeller match that make it work.
Valve Adjustment
Valve clearance adjustment and tune ups that restore compression, economy and starting on high hour engines.
Engine Diagnostics: common questions
My engine is running rough but there is no warning light. Can you still diagnose it?
Yes, and this is common on older mechanical engines with no electronic management at all. Rough running gets traced through compression, injector condition, fuel delivery and valve clearance.
Can you read my engine's computer?
In most cases yes. I came out of a Volvo Penta dealer and have worked across the common marine engine management systems for 20 years.
How long does a diagnostic visit take?
Plan on a half day for a single engine including a run under load. Twin installations and intermittent faults take longer, because an intermittent fault has to be caught in the act.
Tell me what the engine is doing
Describe the symptom on the phone and most of the time the problem is narrowed before I arrive. Surveys are booked around your sea trial date.