This maintenance manual covers the Iveco NEF Series engines, specifically models N40, N45, N60, N67 ENT, and NEF 60 TE2. These engines are engineered for robust performance and reliability, forming the backbone of various industrial and commercial applications. The NEF Series represents Iveco's commitment to advanced engine technology, offering a range of displacements from approximately 3.9L to 6.7L, with variable power outputs tailored to specific operational demands. This manual is designed to support the longevity and optimal functioning of these powerful engines. The purpose of this comprehensive maintenance manual is to provide essential information for the upkeep and repair of your Iveco NEF Series engine. It details preliminary checks, running-in procedures, and guidance for engine malfunctions and long-term storage restarts. Furthermore, the manual includes information on control systems, engine management diagnosis, detailed service intervals, and oil capacity specifications. Troubleshooting guidance is also provided to assist in identifying and resolving potential issues, ensuring efficient operation and maintenance for owners and technicians alike.