🏷️ Basic Information

Make:

BMW

Model:

525i

Year:

1991

Chassis Code:

E34

Engine Code Series:

M50

👋 Introduction

Market Segment:

Executive/Luxury Sedan and Estate segment.

Key Competitors:

Mercedes-Benz W124 E-Class, Audi V8 (later A8), Lexus LS 400, Jaguar XJ.

Vehicle Philosophy:

BMW's 'Ultimate Driving Machine' philosophy, focusing on performance, handling, and driver engagement within the luxury segment.

Powertrain Emphasis:

Inline-six engine known for its smoothness, power delivery, and durability.

Target Audience:

DIY enthusiasts, independent repair shops, and professional BMW technicians.

📋 Manual Details

Primary Coverage:

BMW 525i (E34) Sedan and Touring

Secondary Coverage:

Potentially applicable to other E34 models with similar engine/drivetrain configurations

Estimated Pages:

Varies by specific publication; typically 800-1500 pages for comprehensive workshop manuals

Type:

Service Repair Workshop Manual

Language:

English

Format:

Likely Digital (PDF) or Printed Book

📖 Manual Coverage

Engine:

M50B25 inline-6 engine (2.5L), including fuel injection, ignition, cooling, lubrication, emissions control

Transmission:

Manual and Automatic transmissions, clutch, driveshafts, differential

Suspension:

Front and rear suspension systems, shock absorbers, springs, control arms, bushings, steering system

Brakes:

Front and rear disc brakes, ABS (Anti-lock Braking System), brake hydraulics, parking brake

Electrical:

Complete electrical system, battery, alternator, starter, lighting, fuses, relays, wiring diagrams, ECUs, sensors

Bodywork:

Body panel removal and installation, doors, windows, locks, hinges, interior trim, exterior trim, climate control system (HVAC)

Chassis:

Frame and body structural components

Maintenance:

Scheduled maintenance, oil changes, filter replacements, fluid checks and changes, tune-ups

Diagnostics:

Troubleshooting guides, symptom-based diagnostics, error code interpretation (where applicable)

Repair:

Step-by-step repair procedures for all major mechanical and electrical components

Overhaul:

Engine, transmission, and differential overhaul procedures

Adjustment:

Valve adjustments (if applicable to M50 variant), idle speed, parking brake adjustments

Troubleshooting:

Detailed troubleshooting flowcharts and common problem resolutions

Depth:

Comprehensive; covers everything from basic maintenance to full engine and transmission rebuilds, including detailed wiring diagrams and diagnostic procedures.

📊 Manual Specifications

Digital Format Details:

If PDF: Searchable text, high-resolution diagrams, easily navigable sections.

Print Quality Details:

If Printed: High-quality paper stock, clear and legible diagrams, durable binding.

Binding Type Details:

If Printed: Spiral-bound for lay-flat use in a workshop environment or perfect bound.

Paper Type Details:

If Printed: Matte or semi-gloss paper for reduced glare and durability.

⚙️ Engine Specifications

Engine Code:

M50B25

Engine Type:

Naturally Aspirated, Inline 6-Cylinder, Dual Overhead Camshafts (DOHC), 24 Valves

Displacement:

2494 cc (2.5 Liters)

Bore X Stroke:

84.0 mm x 90.0 mm

Compression Ratio:

8.8:1 (standard)

Horsepower:

189 hp @ 5900 rpm (DIN)

Torque:

245 Nm (181 lb-ft) @ 4200 rpm (DIN)

Fuel Delivery:

Bosch Motronic Electronic Fuel Injection (EFI)

Fuel Type:

Unleaded Gasoline (91 Octane RON recommended)

Coolant Type:

BMW Blue Antifreeze/Coolant (Ethylene Glycol based)

Oil Capacity:

6.5 Liters (6.9 US Quarts) with filter change

Recommended Oil Viscosity:

SAE 5W-30 or 10W-40 (refer to manual for specific climate/service recommendations)

Ignition Type:

Distributorless Ignition System (DIS) with coil-on-plug or coil pack setup

🔧 Transmission

Transmission Type:

5-Speed Manual (Getrag 260/5)

Transmission Type:

4-Speed Automatic (ZF 4HP22)

Manual Gear Ratios:

Refer to manual for specific ratios (e.g., 3.71:1, 2.12:1, 1.43:1, 1.00:1, 0.81:1)

Automatic Features:

Electronic control, Sport/Economy mode selection

Manual Transmission Fluid:

GL-4 or GL-5 Hypoid Gear Oil, SAE 75W-90 or 80W-90 (refer to manual for exact BMW spec)

Automatic Transmission Fluid:

Dexron III (or equivalent specification specified by BMW)

📐 Dimensions

Length:

4720 mm (185.8 inches)

Width:

1751 mm (68.9 inches)

Height:

1412 mm (55.6 inches)

Wheelbase:

2794 mm (110.0 inches)

Front Track:

1472 mm (57.9 inches)

Rear Track:

1486 mm (58.5 inches)

Curb Weight:

Approx. 1560-1600 kg (3440-3527 lbs) depending on transmission and options

Gross Vehicle Weight Rating:

Refer to vehicle data plate; typically around 2000-2100 kg (4409-4630 lbs)

Trunk Capacity:

Approx. 460 Liters (16.2 cu ft)

Wheelbase:

Standard: 7Jx15 ET20, Optional: 7.5Jx16 ET20 or similar

Bolt Pattern:

5x120 mm

Tire Size Standard:

205/65VR15

Tire Size Optional:

225/55VR16

🛡️ Safety Features

Crash Test Data:

Limited official government crash test data available for this specific model year; relies on contemporary automotive journalist reviews and internal BMW testing.

ABS:

Standard Anti-lock Braking System (ABS)

Traction Control:

Optional ASC (Automatic Stability Control) or ASC+T (Traction Control)

Airbags:

Driver's side airbag was optional, passenger airbag was not commonly available on this generation.

Seatbelts:

Three-point inertia-reel seatbelts front and rear.

Body Structure:

Reinforced safety cage, crumple zones.

💡 Technology Features

Audio System:

BMW Bavaria C Business or Professional cassette radio, optional CD changer.

Climate Control:

Manual or optional Automatic Climate Control (ACC) with cabin microfilter.

Cruise Control:

Standard or optional electronic cruise control.

Parking Sensors:

Not available on this model year; park distance control was a later innovation.

Exterior Features:

Power-adjustable mirrors, optional heated mirrors, electric sunroof, power antenna.

🔧 Maintenance

Oil Change Interval:

Typically 10,000-15,000 miles or 12-24 months, depending on driving conditions and oil used (refer to manual for specific BMW recommendations).

Spark Plug Replacement:

Around 60,000 miles (for standard spark plugs, platinum/iridium may differ).

Coolant Flush:

Every 2-3 years or 30,000-50,000 miles.

Timing Belt Chain:

M50 engines use a timing chain, which is designed for the life of the engine but may require tensioner or guide replacement over time. The manual will detail inspection.

Brake Fluid:

DOT 4 (refer to manual for specific BMW fluid designation, e.g., DOT 4 Plus)

Power Steering Fluid:

ATF Dexron II/III or BMW-specific Pentosin CHF 11 S (check manual as variations existed).

Coolant Capacity:

Approx. 8.0 Liters (8.5 US Quarts)

Common Wear Items:

Vibration dampers, intake manifold gaskets, vacuum hoses, suspension bushings (control arm bushings, subframe bushings), VANOS system (if equipped on later M50 variants), radiator support bushings, fuel pump, fuel injectors.

Electrical Gremlins:

Common in older European cars; issues with wiring harness degradation, sensor failures, and module issues are detailed in the manual.

Oil Leaks:

Valve cover gaskets, oil pan gaskets, rear main seals are common leak points.

📚 Vehicle History

Bmw Legacy:

BMW's long-standing reputation for engineering excellence, sporty driving dynamics, and premium build quality.

E34 Generation:

The E34 generation of the 5 Series, produced from 1987 to 1996, represented a significant step forward in styling, technology, and refinement over its predecessor (E28).

525I Positioning:

The 525i was a core model in the E34 lineup, offering a balance of performance, luxury, and value, powered by the new M50 engine introduced in late 1989/early 1990.

Production Years E34:

1987-1996

Production Location:

Dingolfing, Germany and other BMW assembly plants worldwide.

🏆 Awards & Recognition

Automotive Press:

Consistently praised by automotive press for its balanced chassis, refined powertrain, and luxurious interior, often cited as a benchmark for sport sedans of its era.

Longevity Reputation:

The E34 platform and M50 engine are known for their robustness and potential for high mileage with proper maintenance, making them a desirable classic BMW.

Manual Quality:

Represents official BMW factory service information or a high-quality reproduction of it, ensuring accuracy and completeness.