This workshop repair service manual covers Isuzu 4HK1 and 6HK1 diesel engines. These engines are known for their robust inline 4-cylinder (4HK1) and 6-cylinder (6HK1) configurations, featuring common rail direct injection and typically a turbocharged design. The 4HK1 displaces approximately 3.0L, while the 6HK1 is around 5.2L, providing reliable power for various applications. These engines are engineered for durability and efficiency, making them a trusted choice for demanding operational environments. This comprehensive manual is designed for technicians, mechanics, and DIY enthusiasts. It provides detailed information on engine service, maintenance, and troubleshooting for the Isuzu 4HK1 and 6HK1 diesel engines. Coverage includes diagnostic procedures, repair instructions, and technical specifications to ensure optimal performance and longevity. By following the guidelines within this manual, users can effectively maintain and repair their vehicles, ensuring they remain in peak operating condition.