The BMW M3, specifically the E30 chassis code produced between 1981 and 1992, stands as an iconic homologation special celebrated for its motorsport pedigree and exceptional driving dynamics. Developed by BMW Motorsport GmbH, this performance compact sedan and coupe was engineered for racing, featuring distinct design elements like flared wheel arches, an integrated front air dam, and a rear spoiler to enhance its aerodynamic profile. Powered by a naturally aspirated 2.3-liter S14 inline-4 engine, the M3 delivered robust performance, making it a formidable competitor against models like the Ford Sierra RS Cosworth and Audi Quattro. Its engineering quality and focus on driver engagement have cemented its status as a highly sought-after modern classic. This comprehensive service and repair manual provides detailed English-language guidance for the BMW M3 (E30). It covers all essential mechanical and electrical systems, including in-depth diagnostics and repair procedures for the S14 engine, the Getrag 265 5-speed manual transmission, and the Bosch Motronic fuel injection system. The manual also details maintenance schedules, troubleshooting steps for common issues such as oil sludge and subframe mount wear, and specifications for suspension, brakes, and the electrical system. With expert-level technical depth, including torque specifications and clearances, this manual is an indispensable resource for owners, mechanics, and technicians aiming to maintain and restore the performance and reliability of their E30 M3.