2003 Buick Regal Service and Repair Manual

This factory service and repair manual for the 2003 Buick Regal deals with two trims of the four-door sedan, GS and LS. Either one uses a gasoline 3.8L V6 with overhead valves, either naturally aspirated or supercharged. Specifications and torque values for the engine and cooling system, procedures for the fuel and ignition systems, and wiring diagrams and diagnostics for the electrical system make up its reach, with the transmission, brakes, steering and suspension included.

Engines covered

• 3.8L V6 (231 cu in) — OHV, naturally aspirated, gasoline
• 3.8L V6 (231 cu in) — OHV, supercharged, gasoline

Body styles covered

• 4-door sedan

Trims covered

• GS
• LS

Known issues on the 2003 Regal. The federal record holds 3 recalls for the 2003 Regal, and they share one theme: oil reaching a hot exhaust manifold. On certain naturally aspirated cars the oil could arrive under hard braking; on certain supercharged cars a front rocker cover gasket that runs hot could seep. In both cases a flame could reach the plastic spark plug wire channel and spread. The third recall covered certain cars already repaired for this, fitting an improved front valve cover and gasket. Of 101 owner complaints, 35 concern the electrical system and 26 the engine; 5 reported a crash, 14 a fire and 5 an injury. The engine, cooling and electrical systems are covered with procedures and wiring diagrams.