This workshop manual covers the Volvo Penta MD21A, MD32A, AQD21A, and AQD32A marine diesel engines. Engineered for marine propulsion, these internal combustion engines are built to deliver reliable performance in demanding maritime environments. Their robust construction and efficient diesel operation make them a trusted choice for boat owners and operators seeking dependable power. This comprehensive manual provides essential information for the maintenance, repair, and servicing of your Volvo Penta engine. It details basic repairs through to full rebuild procedures, offering clear guidance for mechanics and technicians. The English-language content ensures accessibility for a wide range of users, enabling them to keep their engines in optimal working condition and ensure continued operational integrity.