This manual covers the Volvo B23 engine, a versatile internal combustion powerplant known for its robust construction and reliable performance. Designed with a 4-cylinder configuration and approximately 2.3 liters of displacement, the B23 engine offers a balance of power and efficiency suitable for various applications. Its engineering prioritizes durability and ease of maintenance, making it a dependable choice for its intended use. Specific variants may feature different valvetrain designs, fuel delivery systems, and transmission compatibilities, reflecting its adaptability across different vehicle models and generations. The purpose of this English-language Service Manual (WSM) is to provide comprehensive technical information for the repair and maintenance of the Volvo B23 engine. It details essential procedures, specifications, and guidelines necessary for owners, mechanics, and technicians. Coverage includes in-depth repair information, routine maintenance schedules, troubleshooting guidance, and technical data such as engine specifications, fluid capacities, and component details. This manual is an indispensable resource for ensuring the optimal performance, longevity, and safe operation of the Volvo B23 engine.