This manual covers the Volvo Penta AQ151, an internal combustion engine designed for repair, maintenance, rebuilding, refurbishment, and restoration. Its robust engineering ensures reliability for various applications. While specific production years are not detailed, the AQ151 is recognized for its quality and performance in its intended use. This Full Service Repair Manual provides comprehensive guidance in English for the Volvo Penta AQ151. It details diagnostic procedures, repair steps with numbered instructions and illustrations, and troubleshooting information integrated with electrical service and wiring diagrams. The manual includes safety notes, cautions, and warnings, along with a numbered table of contents for efficient navigation. It is designed to assist owners, mechanics, and technicians in maintaining and repairing the vehicle effectively.