This manual covers the Mitsubishi 6D16 Diesel Engine, manufactured by Mitsubishi Heavy Industries. This inline 6-cylinder diesel engine is designed for robust performance and reliability, specifically for use in Mitsubishi Forklift Trucks. Its engineering quality ensures efficient operation for demanding industrial applications, making it a dependable power source for models such as the FD80, FD90, FD100, FD115, FD135, and FD150A series forklifts. The purpose of this English-language Service Repair Manual is to provide comprehensive guidance for the maintenance and repair of the 6D16 Diesel Engine. It details procedures for the engine itself, lubrication, fuel and engine control systems, cooling, intake and exhaust, electrical systems, and special equipment. This manual is an essential resource for owners, mechanics, and technicians, offering the necessary technical specifications and service information to ensure the optimal performance and longevity of the engine.