Fuel Dilution may arise from multiple operating, fluid, sampling or analytical causes. The pattern, rate of change and correlated evidence determine the most credible explanation.
Start with the observation
Confirm sample identity, method, units, service interval and historical baseline. A single abnormal parameter rarely confirms root cause, and a plausible explanation should predict other evidence that can be checked.
Differential diagnosis
| Possible cause | Supporting indicators | Confirming tests | Immediate response | Long-term corrective action |
|---|---|---|---|---|
| Injector leakage | Low viscosity | fuel dilution | Assess safe operation | Correct the confirmed source rather than the isolated number |
| Incomplete combustion | Reduced flash point | flash point | Investigate fuel and combustion systems | Establish a follow-up sampling point and timing |
| Excessive idling | Abnormal fuel economy | kinematic viscosity | Assess safe operation | Document maintenance so the post-action trend can be evaluated |
| Post-injection | Low viscosity | fuel dilution | Investigate fuel and combustion systems | Correct the confirmed source rather than the isolated number |
Confirming and supporting evidence
Confirming tests
Supporting indicators
- Low viscosity
- Reduced flash point
- Abnormal fuel economy
Immediate and corrective actions
- 01Assess safe operation
- 02Investigate fuel and combustion systems
- 03Correct the confirmed source rather than the isolated number
- 04Establish a follow-up sampling point and timing
- 05Document maintenance so the post-action trend can be evaluated
False positives and context checks
- Non-representative sample
- Changed method or laboratory
- Recent top-up or overhaul
- Container or sampling-tool contamination
References and method context
References identify authoritative source families; they do not reproduce protected procedures or acceptance tables. Verify the current official edition before procedural or conformity use.