1987 Buick Grand National Shop Manual

The 1987 Buick Grand National Shop Manual provides comprehensive technical information for the iconic turbocharged V6 performance sedan. This manual covers the 3.8L turbocharged engine, Turbo-Hydramatic 200-4R transmission, chassis, electrical systems, suspension, brakes, and all mechanical components. Below are key sections for specifications, maintenance procedures, troubleshooting, and repair guidelines.

Vehicle Specifications

Key technical data for the 1987 Buick Grand National including engine, transmission, and performance specifications.

Engine Systems

Detailed information on the 3.8L turbocharged V6 engine, including service procedures and component specifications.

1. Engine identification: LG3 code with sequential fuel injection
2. Turbocharger system: Garrett TB0348 turbo with wastegate
3. Cooling system: Heavy-duty radiator with electric fan
4. Ignition system: High-energy electronic ignition
5. Lubrication system: High-volume oil pump with cooler

WARNING! Turbocharger components operate at high temperatures; allow cooling before service. Use proper safety equipment.

Transmission & Drivetrain

Service procedures for the Turbo-Hydramatic 200-4R transmission and rear axle assembly.

1. Transmission fluid: Dexron II recommended
2. Shift points: Electronically controlled
3. Torque converter: Lock-up type with 12-inch diameter
4. Drive shaft: Balanced steel with U-joints
5. Rear differential: Limited-slip with 8.5-inch ring gear

CAUTION! Always support vehicle properly with jack stands when working underneath.

Fuel & Turbo System

• Fuel Pressure: 38-44 psi with vacuum hose disconnected
• Turbo Boost: Maximum 14.5 psi
• Injectors: Bosch design, 30 lb/hr flow rate
• Fuel Pump: In-tank electric with high-pressure capability
• Intercooler: Not equipped (air-to-air intercooler not available until 1987 GNX)
• Wastegate: Integral with turbo housing
• ECM: GM 1226870 computer with boost control

Electrical Systems

Wiring diagrams and service procedures for all electrical components including ECM, sensors, and charging system.

Key Components: ECM (Engine Control Module), MAF sensor, knock sensor, turbo boost solenoid, alternator (100 amp), battery (maintenance-free).

Diagnostic: ALDL connector under dash for trouble codes. Charging: 100-amp CS-130 alternator. Starting: High-torque starter motor. Lighting: Sealed beam headlights with composite rear lights.

Suspension & Steering

Front and rear suspension service with power steering system specifications.

1. Front suspension: MacPherson strut with coil springs
2. Rear suspension: Torque arm with Panhard rod
3. Steering: Power-assisted recirculating ball
4. Wheel alignment: Factory specifications provided
5. Bushings: Rubber with polyurethane available

Tip: Check for worn suspension components during tire rotation intervals.

Brake Systems

Service procedures for front disc and rear drum brakes with power booster.

1. Front brakes: 10.5-inch rotors with single-piston calipers
2. Rear brakes: 9.5-inch drums with self-adjusting mechanism
3. Master cylinder: Dual-circuit with proportioning valve
4. Brake fluid: DOT 3 recommended
5. Parking brake: Cable-operated rear system

WARNING! Always bleed brake system completely after service. Test brakes at low speed first.

Body & Interior

Body panel alignment, interior trim, and electrical accessory service information.

Maintenance Schedule

Recommended service intervals for oil changes, filter replacement, and system inspections.

CAUTION! Use only factory-specified fluids and filters for optimal performance and longevity.

Troubleshooting Guide

Diagnostic Codes: Use ALDL connector to retrieve ECM trouble codes.

Technical Support: Buick service department or qualified Grand National specialist recommended.