This service and repair manual covers Mitsubishi diesel engines from the L3A, L3C, and L3E families. These naturally aspirated, water-cooled engines utilize direct injection and forced lubrication systems. While specific model years and applications are not detailed, these engines are designed for reliability and efficient operation, likely in industrial or specialized equipment where their compact 3-cylinder configuration and estimated 10-20 HP output are beneficial. This comprehensive manual provides essential information for the maintenance and repair of these Mitsubishi engines. It details critical procedures, technical specifications, and troubleshooting guidance necessary for optimal performance and longevity. Owners, mechanics, and technicians will find detailed instructions on lubrication, filter replacement, service intervals, and other vital aspects of engine care, ensuring the continued dependable operation of the equipment.