🏷️ Basic Information

Make:

Porsche

Model:

928

Variants Covered:

S, S4, GT, GTS

Engine Code General:

M28 (V8)

👋 Introduction

Market Segment:

Luxury Grand Tourer, Performance Car

Key Competitors:

Ferrari 400/412, Aston Martin V8 Vantage, BMW 6 Series (E24), Jaguar XJ-S

Unique Selling Points:

Front-engine, rear-wheel-drive transaxle layout, V8 engine, advanced technology for its era, exceptional Grand Touring capabilities.

📋 Manual Details

Manual Type:

Workshop Manual / Service Manual / Repair Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine Systems:

Engine mechanical (cylinder head, block, crankshaft, pistons, connecting rods), Fuel system (injection, pumps, injectors, lines), Ignition system (coils, plugs, distributors, ECU), Cooling system (radiator, water pump, thermostat, hoses), Lubrication system (oil pump, oil filter, oil cooler), Emission control systems, Turbocharger (if applicable).

Transmission Systems:

Manual and Automatic Transmissions: Gearbox overhaul, clutch operation, torque converter, transmission control modules, drive shafts, differentials, final drive.

Chassis Systems:

Suspension (front and rear McPherson struts, trailing arms, dampers, springs), Steering system (power steering, steering rack, column), Brakes (ABS, caliper overhaul, pad replacement, rotor specifications, hydraulic system), Wheels and tires.

Electrical Systems:

Wiring diagrams, fuse and relay locations, lighting systems, battery, alternator, starter motor, instrument cluster, ECUs, body control modules, power windows, seats, mirrors, climate control systems, audio systems.

Body And Interior:

Body panels, doors, hood, trunk, glass replacement, interior trim, seats, dashboard, climate control vents, safety equipment (airbags, seatbelts).

Maintenance Procedures:

Scheduled maintenance tasks, oil and filter changes, spark plug replacement, belt inspection and replacement, fluid level checks and top-ups, brake pad and rotor replacement, tire rotation and balancing.

Repair Procedures:

Engine disassembly and reassembly, transmission overhaul, suspension component replacement, brake caliper rebuilding, electrical component diagnosis and replacement, fuel system repair, cooling system leak repair.

Troubleshooting Guides:

Diagnostic procedures for common symptoms, fault code interpretation, step-by-step troubleshooting trees for various systems.

Technical Specifications Data:

Torque specifications for fasteners, fluid capacities, clearances, tolerances, diagnostic values, wiring resistance values.

Depth Of Coverage:

Comprehensive, covering routine maintenance to complete engine and transmission rebuilds, including detailed diagnostic procedures and electrical schematics.

📊 Manual Specifications

File Type:

PDF

Searchability:

Likely text-searchable (depending on source scan quality)

Printability:

Printable pages for workshop use

Binding Type:

N/A (Digital Download)

Paper Type:

N/A (Digital Download)

⚙️ Engine Specifications

Engine Type:

V8, Naturally Aspirated (S, S4, GT, GTS variants)

Displacement:

4.5L (S), 5.0L (S4, GT, GTS)

Horsepower S4:

306 hp @ 6000 rpm (approx.)

Torque S4:

311 lb-ft @ 4500 rpm (approx.)

Horsepower Gts:

306 hp @ 6000 rpm (approx., Euro Spec), 292 hp (US Spec)

Torque Gts:

311 lb-ft @ 4500 rpm (approx., Euro Spec), 302 lb-ft (US Spec)

Fuel Delivery:

Bosch LH-Jetronic fuel injection

Fuel Type:

Premium Unleaded Gasoline

🔧 Transmission

Transmission Type:

5-speed Manual (GT) / 4-speed Automatic (Tiptronic on some S4/GTS)

Transmission Type:

4-speed Automatic (standard on S4)

Transaxle Layout:

Rear transaxle (engine front, gearbox rear)

📐 Dimensions

Length:

4790 mm (approx.)

Width:

1790 mm (approx.)

Height:

1280 mm (approx.)

Curb Weight S4 Auto:

1650 kg (approx.)

Curb Weight Gts Manual:

1600 kg (approx.)

🛡️ Safety Features

Crash Test Data:

Limited official crash test data available for this era, but designed with robust construction and safety features for its time.

Active Safety:

Anti-lock Braking System (ABS), excellent weight distribution for handling.

Passive Safety:

3-point seatbelts, reinforced safety cage, driver's side airbag (later models/options), impact-absorbing bumpers.

💡 Technology Features

Infotainment System:

Period-appropriate cassette/radio, optional CD players on later models. Often upgraded in modern restorations.

Driver Assistance Features:

Cruise control, ABS, power steering.

Connectivity Features:

None in the modern sense; analog systems and basic electronics.

🔧 Maintenance

Oil Change Interval:

Every 7,500 miles or 12 months (refer to manual for specific variant recommendations)

Timing Belt Interval:

Every 30,000 miles or 3 years (critical for engine longevity)

Engine Oil Type:

API SG or higher, SAE 10W-40 or 5W-40 synthetic recommended (check manual for exact viscosity and capacity)

Coolant Type:

Porsche-approved G12 or equivalent (typically ethylene glycol-based with corrosion inhibitors)

Brake Fluid Type:

DOT 4 (high-performance synthetic)

Transmission Fluid Auto:

Dexron III/VI or Porsche-approved ATF (check manual for specific PN)

Transmission Fluid Manual:

GL-4 or GL-5 gear oil (specific viscosity depends on temperature, refer to manual)

Common Wear Items:

Timing belt tensioner, water pump, starter motor, fuel pump, ignition components, cooling hoses, fuel lines, electrical connectors, window regulators.

Specific Model Issues:

S4/GTS models can experience DME (Digital Motor Electronics) issues, catalytic converter failure, and aging fuel injection components. Early models may have less robust AC systems.

Timing Belt Kit Part Number Example:

Porsche OEM or Gates equivalent (e.g., 92810520100 for belt, 92810531100 for tensioner)

Oil Filter Part Number Example:

Mahle OC283 or Porsche OEM (e.g., 92810720103)

📚 Vehicle History

Porsche Legacy:

Porsche's history is deeply rooted in motorsport and high-performance sports cars. The 928 represented a departure from their traditional rear-engine sports car formula.

928 Development:

Conceived as a successor to the 911, the 928 was Porsche's first production V8-powered car and the first to feature a transaxle layout. It evolved significantly from its initial 1977 introduction to the GTS.

Production Years:

1978-1995

Production Variants:

928, 928 S, 928 S2, 928 S3, 928 S4, 928 GT, 928 GTS

🏆 Awards & Recognition

Automotive Awards:

While not extensively awarded like some later models, the 928 was recognized for its innovative engineering and GT capabilities, earning praise from automotive journalists upon its release.

Performance Reviews:

Consistently praised for its high-speed stability, comfortable ride, and powerful V8 engine, though early transmissions and cooling systems were noted as areas requiring attention.