🏷️ Basic Information

Make:

Porsche

Model:

928

Body Style:

2-door grand tourer coupe

Engine Code Primary:

M28

Transmission Code Primary:

BorgWarner K26 turbo (later)

👋 Introduction

Positioning:

The Porsche 928 was a groundbreaking luxury grand tourer, positioned as Porsche's flagship model for many years, aiming to compete with cars like the Jaguar XJ-S, Mercedes-Benz SL, and BMW 6 Series. It represented a departure from Porsche's traditional rear-engine sports car formula.

Competitors:

Jaguar XJ-S, Mercedes-Benz R107/C126 (SL/SEC), BMW E24 (6 Series), Aston Martin V8.

Features:

Front-engine V8, rear transaxle for improved weight distribution, advanced (for its time) engineering, luxurious interior, innovative design.

📋 Manual Details

Primary Coverage:

Porsche 928 Service and Repair

Estimated Page Count:

Varies significantly by year and revision, typically hundreds to over a thousand pages for comprehensive sets.

Type:

Service Manual / Repair Manual

Language:

Likely English, but official Porsche manuals were also produced in German, French, and other languages.

Format:

PDF (Digital Electronic Book)

📖 Manual Coverage

Engine Mechanical:

Detailed overhaul procedures, component diagnostics, timing belt replacement, cooling system, lubrication system, fuel system (injection, pumps, injectors), exhaust system.

Engine Management:

Ignition system, electronic control unit (ECU) diagnostics, sensor testing (e.g., knock sensor, camshaft position sensor).

Transmission:

Automatic transaxle (initially) and manual transaxle systems, overhaul, diagnostics, fluid specifications, torque converter clutch operation, shift lock system.

Drivetrain:

Front differential, drive shafts, axle hubs, seals, U-joints (if applicable).

Suspension:

Front and rear suspension systems, shock absorbers, control arms, bushings, springs, wheel alignment specifications, stabilizer bars.

Brakes:

Brake system diagnostics, master cylinder, brake booster, calipers, pads, rotors, brake fluid specifications, ABS system (if equipped), parking brake.

Steering:

Power steering system, steering column, steering rack/gearbox, steering sensors, associated linkages.

Electrical System:

Charging system (generator/alternator), starting system (starter motor, switch), battery, lighting system (headlamps, taillamps, interior lights), horns, infotainment systems (radio receiver, amplifier, speakers), power mirrors, power windows, power door locks, antenna systems.

Body And Interior:

Body repair procedures, doors, windows (including quarter windows, back door glass), sunroof system, seat belts, interior trim, headlining, instrument panel, combination meter, airbags (SRS system, airbag sensors).

Climate Control:

Air conditioning system (refrigerant, compressor, condenser, blower, heater core), heater and air conditioner controls, ventilation systems.

Safety Systems:

Supplemental Restraint System (SRS), airbag deployment sensors, seat belt warning systems, skid control sensors, yaw rate sensors.

Wheels And Tires:

Wheel and tire system, tire pressure monitoring (if applicable), wheel lug nut torque specifications, tire sizes.

Maintenance:

Oil changes, filter replacements, fluid checks and top-offs, spark plug replacement, belt inspections and replacements, brake fluid flush, coolant flush.

Troubleshooting:

Diagnostic procedures for common drivability issues, electrical faults, and mechanical failures. Includes diagnostic trouble codes (DTCs) where applicable.

Repair And Overhaul:

Detailed instructions for component removal, disassembly, repair, reassembly, and installation of major systems like the engine, transmission, suspension, and brakes.

Wiring And Schematics:

Comprehensive wiring diagrams and schematics for all vehicle electrical systems, essential for diagnosing electrical issues and performing wire harness repairs.

Specifications:

Torque specifications for all fasteners, critical clearances, fluid capacities, electrical specifications, and diagnostic data.

Depth:

Extensive and highly detailed, covering everything from routine maintenance to full engine and transmission rebuilds. Suitable for professional mechanics and advanced DIY enthusiasts.

📊 Manual Specifications

Format:

PDF

Quality:

High-resolution scans of original factory manuals, ensuring clarity of text, diagrams, and illustrations. Searchable text functionality is often a key feature of good PDF manuals.

Binding:

N/A (Digital Format)

Paper Type:

N/A (Digital Format)

⚙️ Engine Specifications

Engine Type:

Naturally aspirated V8, later turbocharged variants

Displacement Early:

4.5 liters (4477 cc)

Displacement Later:

4.7 liters (4664 cc), 5.0 liters (4957 cc), 5.4 liters (5311 cc)

Horsepower Early:

Approx. 219-234 hp (DIN)

Horsepower Later:

Approx. 280-326 hp (DIN) for naturally aspirated, up to 330 hp for S models, and 310 hp for Turbo

Torque Early:

Approx. 280-300 lb-ft (DIN)

Torque Later:

Approx. 300-330 lb-ft (DIN) for naturally aspirated, up to 350 lb-ft for S models, and 375 lb-ft for Turbo

Injection:

Bosch L-Jetronic (early), Motronic EFI (later)

🔧 Transmission

Type:

Automatic transaxle (initially, Porsche automatic sourced from ZF)

Type:

5-speed manual transaxle (later models became more common and desirable)

Rear Transaxle:

Rear-mounted transaxle for 50/50 weight distribution.

Automatic Transmission Fluid:

Dexron II (or equivalent) is commonly specified for the ZF automatic. Manual transmission typically uses GL-4 gear oil.

📐 Dimensions

Length:

Approx. 4655 mm (183.3 in) for early models, increasing slightly in later years.

Width:

Approx. 1786 mm (70.3 in)

Height:

Approx. 1283 mm (50.5 in)

Curb Weight:

Approx. 1500-1600 kg (3300-3500 lbs), varying by year and options.

Gross Weight Rating:

Typically around 2000-2100 kg (4400-4600 lbs)

🛡️ Safety Features

Crash Test Results:

While formal modern crash test ratings are not directly comparable, the 928 was engineered with a robust chassis and safety features for its era.

ABS:

Anti-lock Braking System (ABS) was optional on early models and became standard on later models.

Airbags:

Driver-side airbag became standard in later production years. Passenger airbags were not widely available.

Seat Belts:

Three-point seat belts with pre-tensioners.

💡 Technology Features

Audio System:

Typically featured high-quality audio systems for its era, often with cassette players and optional amplifiers and premium speaker setups.

Climate Control:

Automatic climate control systems were available, offering sophisticated temperature and fan speed management.

Cruise Control:

Standard cruise control system.

Connectivity:

Limited by modern standards; primarily focused on car-specific systems rather than external device connectivity.

🔧 Maintenance

Oil Change:

Typically every 7,500-10,000 miles (12,000-15,000 km) or annually, depending on driving conditions. Check manual for specific recommendations.

Timing Belt Replacement:

Crucial for V8 engines. Intervals vary by year, often around 30,000-60,000 miles (50,000-100,000 km) or 4-5 years. Failure is catastrophic.

Engine Oil:

10W-40 or 15W-50 synthetic or semi-synthetic oil is commonly recommended, with specific API and ACEA ratings as per manual.

Coolant:

Porsche specified coolant (or equivalent) with a 50/50 mix of antifreeze and distilled water.

Brake Fluid:

DOT 4 or DOT 5.1 brake fluid, depending on model year and system requirements. Flush and replace every 2 years.

Timing Belt Wear:

Premature wear or failure of the timing belt and tensioners is a critical concern, leading to severe engine damage. Regular inspection and timely replacement are paramount.

Electrical Gremlins:

Aging wiring harnesses, aged connectors, and failing relays can lead to intermittent electrical issues affecting various systems.

Fuel System Aging:

Degradation of fuel lines, seals, and fuel pressure regulators can occur with age.

Suspension Bushings:

Worn suspension bushings can lead to vague handling and premature tire wear.

Automatic Transmission:

While robust, older ZF automatics can develop issues with valve bodies, clutches, or solenoids if not properly maintained.

📚 Vehicle History

Heritage:

Porsche AG is renowned for its high-performance sports cars, tracing its roots back to Ferdinand Porsche's early automotive engineering.

Evolution:

Introduced in 1977 as a 1978 model, the 928 evolved through various engine displacements and performance upgrades, including the 4.7L S, 5.0L S2/S3, S4, SE, and the high-performance GT and GTS models. Significant design and mechanical updates occurred throughout its 18-year production run.

Production Years:

1978-1995

Manufacturing Location:

Stuttgart, Germany

🏆 Awards & Recognition

Car And Driver:

Named to Car and Driver magazine's Ten Best list multiple times in the late 1970s and early 1980s.

Design Awards:

Praised for its aerodynamic and modern design, which was ahead of its time.