Technical Article
Scavenge Fire: Causes, Warning Signs and Immediate Actions
A scavenge fire occurs when oil, carbon, or fuel residues ignite in the scavenge space of a two-stroke engine. Warning signs can include rising scavenge temperature, smoke, abnormal exhaust temperature, turbocharger surging, and fire alarm indications. Vessel emergency procedures and maker instructions must be followed immediately.
What causes scavenge fire?
- Accumulated oil, carbon, or unburned fuel in the scavenge space
- Poor combustion, leaking injectors, or broken piston rings
- Excess cylinder lubrication or poor drain condition
- Hot blow-by gases passing into scavenge areas
Immediate action
Follow the vessel's emergency procedure, maker instruction book, and bridge/engine-room communication protocol. Do not open scavenge doors until the engine is stopped, isolated, cooled, and confirmed safe by qualified personnel.
Measurements and acceptance limits
Condition assessment should be based on recorded measurements, visual findings, operating symptoms, and the applicable maker documentation. Acceptable limits should be confirmed against the applicable manufacturer's manual and engine-specific technical documentation.
Need technical assistance?
If inspection, overhaul, troubleshooting, workshop repair, or onboard attendance is required, Dieselmech Group can review the symptoms, engine details, operating history, and available measurements before recommending the next practical step. Contact us at +65 6334 1855, email sales@dieselmech.com.sg, or submit an enquiry through the Contact Us page.
Technical note
This article is for general technical information. Actual procedures, limits, clearances, pressures, temperatures, torque values, and renewal criteria depend on the engine model, configuration, maker revision, service bulletin, vessel procedures, and class requirements. Manufacturer manuals and vessel safety procedures take precedence. Safety-critical work should be carried out by appropriately qualified personnel.
Published by Dieselmech Group Technical Team. For advice on a specific engine or fault, contact our marine engineers.

-DQG-c1Ek.png)