🏷️ Basic Information Identification Make: Porsche Model: 944 Year: 1991 Variant: 944S 👋 Introduction Market Position Positioning: The Porsche 944, particularly the 'S' variant, represented Porsche's move towards a more accessible sports car, blending performance with everyday usability. This manual targets owners and technicians dedicated to maintaining and restoring these iconic vehicles. Competitive Analysis Competitors: Competed with cars like the Nissan 300ZX, Toyota Supra, Mazda RX-7, Chevrolet Camaro/Firebird, and BMW 3 Series of the era. Key Features Vehicle Focus: The 1991 944S is noted for its balanced chassis, rear-wheel drive, and potent four-cylinder engine, offering a distinct driving experience. Manual Benefit: Empowers owners to perform accurate diagnostics and repairs, saving money and ensuring correct procedures are followed, preserving the vehicle's integrity. 📋 Manual Details Coverage Areas Primary Coverage: Workshop Manual / Service Manual Secondary Coverage: Repair, Maintenance, Diagnostics, Troubleshooting, Restoration Page Count Estimated Pages: Likely 1000+ pages (typical for comprehensive workshop manuals of this era) Manual Type Type: Official Porsche Workshop Manual (likely reproduction or digital format of original) Language Language: English Format Digital Format: Downloadable PDF 📖 Manual Coverage Systems Covered Powertrain: Engine (mechanical, fuel, ignition, exhaust), Transmission (manual and automatic, if applicable), Drivetrain (clutch, driveshafts, differential) Chassis: Suspension (front and rear), Steering system, Brakes (hydraulic, ABS), Wheels and Tires Electrical: Wiring diagrams, Lighting, Instrumentation, Power accessories, Battery and charging system, Engine control unit (ECU) and sensors Body And Interior: Body panels, Doors, Windows, Seats, HVAC system, Body control modules Procedures Included Maintenance: Oil changes, Filter replacements, Spark plug service, Fluid checks and changes, Belt inspections and replacement Repair: Engine component replacement (pistons, valves, bearings), Transmission overhaul, Brake caliper and rotor replacement, Suspension component repair, Electrical component troubleshooting and replacement Diagnostics: Troubleshooting charts, Fault code interpretation (OBD I era), Diagnostic procedures for all major systems Specifications And Tolerances: Torque specifications for fasteners, Engine clearances, Measurement specifications for critical components Technical Depth Depth: Comprehensive, covering routine maintenance to complete engine and transmission rebuilds Audience: Professional technicians and experienced DIY enthusiasts 📊 Manual Specifications File Format PDF Quality: Likely high-resolution scans for clear readability; Searchable text functionality is highly desirable for PDF manuals Print Quality Printability: Designed to be printed section by section, or in full if desired Binding Type Binding: N/A (Digital Download) Paper Type Paper Quality: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Type: Naturally Aspirated Inline-4, DOHC Engine Code: M44.43 (for 944S) Displacement: 2.5 Liters (2479 cc) Performance Horsepower: 190 hp (142 kW) @ 6000 rpm Torque: 170 lb-ft (230 Nm) @ 4500 rpm Fuel System Induction: Bosch L-Jetronic Fuel Injection (LH-Jetronic for later variants) Fuel Type: Unleaded Gasoline (Premium Recommended) Engine Construction Block Material: Aluminum Alloy Cylinder Head Material: Aluminum Alloy Cooling System Type: Liquid-Cooled 🔧 Transmission Standard Type: 5-speed Manual Transaxle Optional Type: 4-speed Automatic Transaxle (Tiptronic on some later models, but likely not the 1991 'S' variant as standard). Features Transaxle Design: Rear-mounted transaxle for optimal weight distribution (front engine, rear-wheel drive). 📐 Dimensions Exterior Length: Approx. 4235 mm (166.7 in) Width: Approx. 1720 mm (67.7 in) Height: Approx. 1270 mm (50.0 in) Wheelbase: Approx. 2450 mm (96.5 in) Weights Curb Weight: Approx. 1340 kg (2954 lbs) Weight Distribution: Near 50/50 front/rear due to transaxle layout. 🛡️ Safety Features Ratings Crash Test Data: Limited official crash test data available for this specific year/model from modern standards. Early Porsche safety considerations focused on structural integrity and driver protection. Active Features Braking System: Four-wheel disc brakes; Anti-lock Braking System (ABS) standard on 'S' model. Steering: Power-assisted rack and pinion steering. Passive Features Occupant Protection: Three-point inertia reel seatbelts, supportive front seats, reinforced safety cage construction. 💡 Technology Features Infotainment Audio System: Factory premium sound system with cassette player; early digital displays for climate control and radio presets. Driver Assistance ABS: Standard Anti-lock Braking System (ABS). Cruise Control: Optional or standard depending on trim level. Connectivity OBD System: OBD I (On-Board Diagnostics) system, requiring specific diagnostic tools for fault code retrieval. 🔧 Maintenance Service Intervals Oil Change: Typically every 5,000-7,500 miles or 1 year, whichever comes first. Check manual for exact interval. Timing Belt: Crucial! Replacement every 30,000-50,000 miles or 3-5 years due to interference engine design. Failure can cause catastrophic engine damage. Spark Plugs: Inspect every 15,000 miles, replace as needed (typically every 30,000 miles). Fluid Specifications Engine Oil: Refer to manual, but typically a high-quality synthetic 5W-40 or 10W-40 is recommended. Coolant: Porsche approved G40 or similar long-life coolant (typically 50/50 mix with distilled water). Brake Fluid: DOT 4 Transmission Fluid: Manual: GL-4 or GL-5 gear oil (specific weight determined by manual). Automatic: ATF Type T-III or similar (refer to manual for exact specification). Known Issues Common Problems: Timing belt failure, worn fuel injectors, aging fuel lines, HVAC system issues (blower motor, climate control), electrical gremlins, suspension bushings, clutch slave cylinder leaks, window regulator...