🏷️ Basic Information

Make:

BMW

Model:

520i

Year:

1991

Chassis Code:

E34

Engine Code Typical:

M20B20 (though M50B20 became available in later 520i E34 models, the '91 often refers to the M20 for this specific variant)

👋 Introduction

Market Position:

The BMW 520i (E34) in 1991 represented BMW's mid-size executive sedan offering, known for its blend of comfort, performance, and luxury, competing against rivals like the Mercedes-Benz W124 E-Class and Audi 100.

Competitive Analysis:

The E34 generation was lauded for its sophisticated chassis, rear-wheel-drive dynamics, and build quality, positioning the 520i as a premium, driver-focused option in its segment.

Key Features:

Luxurious interior, refined ride quality, capable handling, iconic BMW design language, and the promise of long-term durability.

Chassis And Suspension:

Advanced multi-link rear suspension and independent front suspension for superior ride and handling characteristics.

📋 Manual Details

Coverage Areas:

All Models/Engines/Trim/Transmissions Types for 1991 BMW 520i (E34)

Specific Engine Variants:

Covers the 2.0L M20B20 engine, and may include diagnostic information relevant to other E34 models if shared systems exist.

Page Count:

Estimated 1000+ pages (typical for comprehensive workshop manuals)

Manual Type:

Workshop Repair Service Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Systems Covered:

Engine Mechanical, Engine Fuel & Emissions, Engine Lubrication & Cooling, Engine Electrical, Ignition System, Clutch, Manual Transmission, Automatic Transmission, Driveshaft & Axles, Suspension (Front & Rear), Steering System, Brakes (Front & Rear), Wheels & Tires, Body (Interior & Exterior), Heating & Air Conditioning (HVAC), Electrical System (Wiring Diagrams, Components), Lighting System, Instrumentation & Information System, Body Control Modules, Safety Systems (ABS if equipped), Diagnostic Procedures

Body Electrical:

Comprehensive wiring diagrams for all circuits, including lighting, power windows, central locking, mirrors, wipers, and instrument cluster.

Climate Control:

HVAC system operation, refrigerant handling (R12 for this era), blower motor, evaporator, condenser, and heater core service.

Procedures Included:

Routine Maintenance, Scheduled Service, Troubleshooting Guides, Diagnostic Flowcharts, Step-by-Step Repair Procedures, Overhaul Instructions, Component Removal & Installation, Torque Specifications, Alignment Procedures, Electrical Component Testing, Wiring Harness Repair, Body Panel Repair & Replacement, HVAC System Servicing, Safety System Diagnostics

Troubleshooting Diagnostics:

Detailed diagnostic flowcharts for common problems, fault code interpretation (OBD-I), and component testing procedures.

Wheel Alignment Specs:

Provides camber, caster, and toe specifications for both front and rear axles, along with adjustment procedures.

Technical Depth:

Comprehensive: Covers basic maintenance to complete engine and transmission rebuilds, advanced electrical diagnostics, and bodywork procedures.

Engine Rebuild Procedures:

Detailed instructions for cylinder head removal/installation, piston and connecting rod replacement, crankshaft and bearing services, and complete engine teardown/assembly.

📊 Manual Specifications

File Format:

PDF

Searchable Text:

Yes (typical for high-quality PDF manuals)

Print Quality:

High Resolution (suitable for printing)

Binding Type:

N/A (Digital Download)

Paper Type:

N/A (Digital Download)

⚙️ Engine Specifications

Primary Engine:

2.0L Inline-6 (M20B20)

Horsepower:

Approx. 129 hp @ 5,800 rpm

Torque:

Approx. 174 Nm (128 lb-ft) @ 4,300 rpm

Fuel System:

Bosch Motronic fuel injection

Fuel Pump Type:

Electric, in-tank

Bore X Stroke:

80.0 mm x 66.0 mm

Compression Ratio:

8.8:1

Valvetrain:

SOHC, 12 Valves

Displacement:

1990 cc (2.0 Liters)

Cooling System:

Pressurized, glycol-based coolant system with engine-driven water pump and thermostatically controlled radiator.

Ignition System:

Electronic ignition (Bosch Motronic) with distributor and ignition coil.

Engine Code:

M20B20

🔧 Transmission

Standard Transmission:

5-speed Manual

Optional Transmission:

4-speed Automatic (e.g., ZF 4HP-22)

Rear Axle Ratio:

Typically around 3.46:1 (varies by transmission and region)

Gear Ratios Manual:

1st: 4.00:1, 2nd: 2.15:1, 3rd: 1.43:1, 4th: 1.00:1, 5th: 0.81:1 (Typical for Getrag 260 gearbox)

📐 Dimensions

Length:

Approx. 4,730 mm (186.2 in)

Width:

Approx. 1,751 mm (68.9 in)

Height:

Approx. 1,410 mm (55.5 in)

Wheelbase:

Approx. 2,760 mm (108.7 in)

Front Overhang:

Approx. 860 mm (33.9 in)

Rear Overhang:

Approx. 1,110 mm (43.7 in)

Curb Weight:

Approx. 1,470 kg (3,240 lbs) for manual transmission

Gross Vehicle Weight Rating:

Approximately 1,950 kg (4,300 lbs)

Front Axle Load:

Approximately 950 kg (2,094 lbs)

Rear Axle Load:

Approximately 1,000 kg (2,205 lbs)

Seating Capacity:

5

🛡️ Safety Features

Safety Ratings:

No standardized crash test ratings equivalent to modern NHTSA/Euro NCAP available for this era, but known for robust construction.

Active Features:

Optional Anti-lock Braking System (ABS)

Traction Control:

Not typically available on the 520i of this year; later models and higher trims featured ASC/ASC+T.

Passive Features:

Reinforced chassis, crumple zones, driver's side airbag (often optional or part of specific packages), seat belts

💡 Technology Features

Infotainment:

Basic AM/FM radio with cassette player, optional CD player, analog climate controls.

Driver Assistance:

Optional cruise control, optional ABS.

Connectivity:

Limited by era; primarily focused on vehicle systems rather than external connectivity.

Onboard Diagnostics:

Early OBD-I system (BMW proprietary), manual will detail diagnostic connectors and procedures.

🔧 Maintenance

Oil Change Interval:

Typically 10,000-15,000 km (6,000-10,000 miles) or annually, depending on driving conditions and oil used. Check manual for specific BMW recommendations.

Spark Plug Replacement:

Refer to manual; typically around 30,000-50,000 km (20,000-30,000 miles) for standard plugs.

Automatic Transmission Service:

Fluid and filter change recommended every 50,000-80,000 km (30,000-50,000 miles).

Engine Oil Type:

API SG or higher, SAE 5W-30 or 10W-40 (consult manual for exact BMW LL specification if applicable)

Coolant Type:

BMW Blue Antifreeze/Coolant or equivalent ethylene glycol-based coolant (50/50 mix with distilled water)

Brake Fluid Type:

DOT 4

Transmission Fluid Manual:

GL-4 Gear Oil (e.g., SAE 75W-90 or 80W-90)

Transmission Fluid Automatic:

Dexron III or equivalent (specific ZF fluid may be recommended)

Known Issues:

Head gasket leaks (M20 engine), cooling system component wear (hoses, thermostat, water pump), fuel pump failure, idle control valve issues, ABS sensor faults, power steering leaks, door panel sag/card sag, seized sunroof motors, instrument cluster pixelation (later models, less common on '91).

Suspension Components:

Wear in control arm bushings, ball joints, and shock absorbers common with age and mileage.

Engine Oil Capacity:

Approx. 4.25 liters (4.5 US quarts) with filter change

Coolant Capacity:

Approx. 7.5 liters (7.9 US quarts)

Automatic Transmission Capacity:

Approx. 7.5 liters (7.9 US quarts) for a full refill

📚 Vehicle History

Brand Heritage:

BMW, established in 1916, has a long history of producing high-performance luxury vehicles, known for 'The Ultimate Driving Machine' slogan.

Model Evolution:

The E34 generation, produced from 1987 to 1996, succeeded the E28 and was succeeded by the E39. It marked a significant design and engineering evolution for the 5 Series.

Design Influence:

Designed by Claus Luthe, the E34 featured a more aerodynamic and contemporary design than its predecessor, with a focus on improved interior space and safety.

Production Period:

1987-1996 (E34 generation)

Manufacturing Locations:

Germany (primarily Dingolfing)

🏆 Awards & Recognition

Recognitions:

The E34 generation was widely praised by automotive press for its driving dynamics, build quality, and elegant design, often featured in 'best of' lists for its era.