<![CDATA[The efficiency and performance of shipboard generators are crucial for safe and uninterrupted vessel operation, and the condition of the exhaust gas is an important indicator of combustion quality and engine health. This study analyses the exhaust gas condition of diesel generator No. 3 (Caterpillar C18) on the offshore vessel Rawabi 49, owned by Rawabi Vallianz Offshore, and its effect on engine power. A descriptive case study was conducted on board for approximately one year, using direct observation of generator operation and inspection of the air intake and exhaust systems, the manufacturer’s specifications and operating limits, and a review of the relevant literature. The observations showed an abnormally high exhaust gas temperature on generator No. 3. Inspection traced the problem to a dirty and clogged air cleaner, which reduced the air flow to the engine, upset the air–fuel ratio, and caused incomplete combustion and a loss of output power. Insufficient maintenance of the generator also forced the engine to work harder under high load, which tends to increase nitrogen oxide and particulate emissions. Eleven factors that can raise exhaust gas temperature were identified, including fuel quality, injector and turbocharger condition, load, cooling, and valve clearance. Regular cleaning or replacement of the air cleaner according to the maker’s schedule, monitoring of air inlet restriction and exhaust temperature, and planned maintenance are recommended to restore engine power, improve fuel efficiency, and reduce emissions.]]>
