🏷️ Basic Information

Make:

BMW

Model:

520i

Year:

1991

Chassis Code:

E34

Engine Code:

M50B20

👋 Introduction

Segment:

Executive sedan, premium mid-size

Target Audience:

Owners seeking to perform their own maintenance and repairs, independent repair shops specializing in BMW vehicles.

Competitors 1991:

Mercedes-Benz W124 E-Class, Audi 100/200, Lexus LS 400 (introduced late 1989, gaining traction), Jaguar XJ

Vehicle Attributes:

Renowned BMW handling ('Ultimate Driving Machine'), refined inline-six engines, robust build quality, comfortable and luxurious interior.

Value:

Provides authoritative guidance for maintaining and repairing a classic BMW, enabling cost savings and preserving vehicle integrity.

📋 Manual Details

Main Topics:

Full service and repair instructions

Estimated Page Count:

Approx. 800-1200 pages (typical for comprehensive BMW E34 manuals)

Type:

Service Repair Workshop Manual

Language:

English

Format:

Digital (likely PDF)

📖 Manual Coverage

Engine:

Engine mechanical, engine management, cooling, lubrication, fuel delivery, ignition system

Transmission:

Manual and automatic transmission overhaul, repair, and adjustment

Drivetrain:

Driveshafts, differential, axles, clutch

Suspension:

Front and rear suspension components, steering system, wheel alignment

Brakes:

Brake system components, ABS (if equipped), hydraulic system, disc/drum brake service

Electrical:

Wiring diagrams, starter, alternator, battery, lighting, instrumentation, power accessories, fuse/relay locations

Body:

Body panels, doors, windows, interior trim, bumpers, chassis adjustments

Heating And Ac:

HVAC system components, refrigerant handling, climate control

Maintenance:

Scheduled maintenance, oil changes, filter replacements, tune-ups

Troubleshooting:

Diagnostic procedures, symptom-based troubleshooting guides, fault code interpretation

Repair:

Component removal and installation, rebuilding procedures, adjustments

Specifications:

Torque specifications, clearances, fluid capacities, electrical values

Depth:

Comprehensive, covering basic maintenance to complete engine and transmission rebuilds, diagnostic procedures for all major systems.

📊 Manual Specifications

File Type:

PDF

Searchable Text:

Likely searchable (depending on OCR quality)

Image Resolution:

High-resolution scans expected for diagrams and illustrations

Binding:

N/A (Digital Format)

Paper:

N/A (Digital Format)

⚙️ Engine Specifications

Engine Type:

Inline 6-cylinder, DOHC, 24-valve

Displacement:

1991 cc (2.0 Liters)

Bore X Stroke:

80.0 mm x 66.0 mm

Compression Ratio:

8.8:1

Horsepower:

129 hp @ 5500 rpm (approximate DIN)

Torque:

180 Nm (133 lb-ft) @ 4300 rpm (approximate DIN)

Fuel Delivery:

Bosch Motronic M2.1 or M2.5 Electronic Fuel Injection (EFI)

Fuel Type:

Unleaded gasoline (RON 95 recommended)

Ignition Type:

Distributorless ignition (DIS) or distributor with coil packs managed by Motronic ECU

Coolant Type:

BMW Blue Antifreeze/Coolant or equivalent G48 ethylene glycol-based coolant

Oil Type:

SAE 15W-40 or 10W-40 API SG/SH or higher (check manual for specific BMW approval)

Oil Capacity:

Approx. 4.5 - 5.0 liters (with filter)

🔧 Transmission

Type:

Getrag 260 5-speed manual transmission

Type:

ZF 4HP22 4-speed automatic transmission

Manual Gear Ratios:

1st: 4.07, 2nd: 2.21, 3rd: 1.40, 4th: 1.00, 5th: 0.81 (typical)

Manual Transmission Fluid:

SAE 75W-90 API GL-4 or GL-5 gear oil (check manual for specific type)

Automatic Transmission Fluid:

ATF Dexron II or III (check manual for exact specification)

📐 Dimensions

Length:

4710 mm (185.4 in)

Width:

1751 mm (68.9 in)

Height:

1410 mm (55.5 in)

Wheelbase:

2799 mm (110.2 in)

Curb Weight:

Approx. 1450-1550 kg (3197-3417 lbs)

Gross Vehicle Weight:

Approx. 1950 kg (4299 lbs)

Wheel Bolt Pattern:

5x120

Wheel Size:

15-inch or 16-inch alloy wheels (common)

Tire Size:

205/60R15 or 225/55R15 (common)

🛡️ Safety Features

Crash Test Results:

NCAP or IIHS ratings for this era are not as standardized or readily available as modern vehicles. Focus on passive safety features.

ABS:

Anti-lock Braking System (optional on early E34, standard on later models)

Traction Control:

Automatic Stability Control (ASC) or Automatic Stability Control + Traction (ASC+T) was an option on higher-spec E34 models, less common on the 520i.

Airbags:

Driver's side airbag (optional or standard depending on market and production date, not universally standard for 1991)

Seatbelts:

3-point inertia-reel seatbelts front and rear

Body Structure:

Reinforced safety cage, crumple zones.

💡 Technology Features

Radio:

Factory BMW AM/FM stereo with cassette player, often with optional CD changer provisions.

Onboard Computer:

Optional On-Board Computer (OBC) displaying fuel consumption, range, average speed, and diagnostic codes.

Cruise Control:

Standard or optional cruise control system.

Climate Control:

Manual or optional automatic climate control (ACC - Automatic Climate Control).

Windows And Mirrors:

Power windows, power adjustable mirrors. Optional heated mirrors.

🔧 Maintenance

Oil Change Interval:

Every 7,500 - 10,000 miles or 12 months (whichever comes first), depending on driving conditions. Check manual for BMW's specific recommendations for this model year.

Spark Plug Replacement:

Typically every 30,000 - 60,000 miles, depending on spark plug type (standard copper vs. long-life)

Coolant Flush:

Every 2-3 years or 30,000-40,000 miles.

Timing Belt Or Chain:

The M50B20 engine utilizes a timing chain, which generally does not have a scheduled replacement interval but requires inspection for wear and tensioner condition.

Brake Fluid:

DOT 3 or DOT 4 (check manual for specific requirement)

Power Steering Fluid:

BMW PSF or equivalent hydraulic fluid (check manual)

Cooling System:

Plastic coolant expansion tanks can become brittle and crack; water pump bearings can fail; heater control valves can leak.

Engine Management:

Mass Air Flow (MAF) sensor issues, idle control valve (ICV) problems, exhaust gas recirculation (EGR) issues (if equipped), sensor failures (crankshaft position, camshaft position).

Electrical System:

Corrosion in electrical connectors (especially ground points), failing window regulators, instrument cluster issues, OBC (On-Board Computer) pixelation.

Suspension And Steering:

Worn control arm bushings, ball joints, tie rods, and shock absorbers are common due to age and mileage. Flex disc (guibo) on driveshaft can degrade.

Interior:

Headliner sagging, dashboard cracks (especially in hot climates), seat bolster wear.

Fuel System:

Leaking fuel injectors, failing fuel pump or pre-filter.

📚 Vehicle History

Bmw Philosophy:

BMW's long-standing reputation for building driver-focused, well-engineered luxury vehicles with sporting prowess.

E34 Introduction:

The E34 generation of the 5 Series was introduced in 1987 (Europe) and 1988 (North America), replacing the E28. It represented a significant step forward in design, aerodynamics, and technology.

E34 Facelift:

The E34 received a facelift in 1994 (LCI - Life Cycle Impulse), with minor styling updates and powertrain revisions. The 1991 model falls into the pre-facelift era.

Production Years:

E34 production ran from 1987 to 1996.

Manufacturing Location:

Germany (primarily Dingolfing plant), South Africa, Thailand, Mexico, and Egypt.

Significance:

The E34 series is considered one of BMW's most robust and well-balanced generations, praised for its driving dynamics and longevity.

🏆 Awards & Recognition

Automotive Press Awards:

While specific awards for the 1991 520i are not widely documented, the E34 generation generally received strong reviews from automotive publications for its driving dynamics, build quality, and refinement, often being compared favorably to its luxury sedan competitors.

Customer Loyalty:

BMW as a brand consistently ranks high in customer satisfaction and loyalty surveys, a testament to the engineering and ownership experience of models like the E34.