RTG engine failure: how to find the root cause
Why RTG engine failures repeat
Replacing the failed part gets the crane back to work, but it rarely removes the cause. When the pressure is to return the RTG to service, the evidence disappears with the old part. A short, structured investigation after each significant failure is what stops the same breakdown from returning.
Step 1: secure the evidence before the repair
- Fault codes and alarm history from the engine controller and the crane control system.
- Engine hours, recent duty and load, and the date and content of the last preventive maintenance.
- Recent changes: replaced parts, a new fuel batch, software or alarm-limit changes.
- Photos of the failed part and its surroundings, plus oil, coolant or fuel samples where relevant.
- The operator's account of what happened and what was heard, seen or smelled.
Step 2: group the failure by system
| System | Typical signs | First checks |
|---|---|---|
| Cooling | High coolant temperature alarm, derating, shutdown | Coolant level and leaks, radiator and charge-air cooler fouling, fan drive, thermostat, airflow in the engine room |
| Fuel | Hard starting, loss of power, hunting | Fuel filters and water separator, fuel quality, tank contamination, lift pump, injectors |
| Air intake and exhaust | Black smoke, low power, high temperature | Air filter condition and restriction indicator, intake leaks, turbocharger, exhaust restriction |
| Lubrication | Low oil pressure alarm, high oil consumption | Oil level and grade, oil cooler, filters, oil analysis |
| Electrical and controls | No start, spurious trips, intermittent alarms | Batteries and connections, starter, charging, sensors, wiring, controller settings |
| Mechanical wear | Knocking, vibration, metal in the oil | Oil analysis, running hours against service interval, mounts and couplings |
Step 3: look across the fleet
If several RTGs show the same alarm or failure, suspect a common cause, such as an alarm setting, a specification, a procedure or the site conditions, before replacing parts one by one.
In one set of investigations at a coastal terminal, repeated engine-room over-temperature alarms across a group of RTGs were traced to a sensor limit that did not suit the site, together with restricted air circulation. The engines themselves were not the problem.
Step 4: ask why until you reach a cause you can control
Here is a worked example. It is illustrative, not a real case.
| Step | Answer |
|---|---|
| Problem | An RTG engine shut down on high coolant temperature during a busy shift. |
| Why 1 | The cooling system could not reject the heat. |
| Why 2 | Airflow through the radiator was restricted. |
| Why 3 | The radiator fins were blocked by dust and salt deposits. |
| Why 4 | Cleaning was not scheduled by condition. The PM only had an hours-based inspection. |
| Why 5 | The PM plan had not been reviewed against the dust and salt conditions at the terminal. |
| Root cause | The maintenance plan did not match site conditions. |
Turn the findings into actions that last
- Corrective: clean the radiator and charge-air cooler and restore normal operation.
- Preventive: add a condition-based cleaning interval and a visual check to the PM, and check the other RTGs for the same issue.
- Sustain: track overheating alarms per RTG each month and review them in the reliability meeting.
- Give every action an owner and a date, and check after a few weeks that the fix held.
Use the manufacturer's service manual for limits and tolerances. This guide is a method, not a specification.
Frequently asked questions
What are the most common causes of RTG engine failure?
Cooling problems, fuel contamination, restricted air intake, lubrication problems, electrical and control faults, and gaps in maintenance. Which one applies depends on your site conditions and duty, so start with the evidence.
How do I know whether a failure is a one-off or a pattern?
Compare failure history by RTG, system and alarm over time. If more than one RTG has had the same failure, treat it as a pattern and look for a common cause.
Should I use 5 Whys or a fishbone for an engine failure?
Often both. A fishbone widens the list of possible causes across categories such as machine, method and environment, and 5 Whys drills into the most likely branch.
Describe the failure or add a photo or file, and RapidRCA builds the 5 Whys, fishbone, actions and report, using the ROOTS method.
Start an RCA
Last updated 14 October 2026. These guides explain a method and give examples. Always follow your equipment manufacturer's manual, your site procedures and applicable regulations.