Market Segment:
Executive/Luxury Sedan
Era:
Late 1980s / Early 1990s Premium European Sedan
Key Competitors:
Mercedes-Benz W124 E-Class, Audi V8 Quattro, Lexus LS 400 (late in the generation's life)
Driving Dynamics:
Renowned for its balanced handling, rear-wheel drive bias, and driver-focused cockpit
Build Quality:
Exceptional build quality and longevity, characteristic of BMW's engineering prowess
Design Philosophy:
Understated elegance, aerodynamic efficiency, and functional interior design
Engine Mechanical:
Complete overhaul, timing, valve adjustments, piston/ring replacement, crankshaft/bearing service, cylinder head reconditioning
Engine Management:
Bosch Motronic (M1.3/M2.1/M2.5/M2.7) fuel injection and ignition systems, sensor diagnostics, ECU troubleshooting, idle control, emissions control
Transmission Manual:
S3.10/S3.26/S3.71/S3.90 gearboxes: clutch, gearbox overhaul, gear shift mechanisms, differential service
Transmission Automatic:
ZF 4HP22/4HP24 automatic transmissions: fluid changes, valve body diagnosis, torque converter, gearbox rebuild procedures
Suspension:
Front strut assemblies, rear multi-link suspension, springs, shock absorbers, control arms, sway bars, power steering system
Brakes:
Front vented discs, rear solid discs (or vented on some 535i), ABS (Anti-lock Braking System) diagnosis and repair, brake fluid flushing, caliper and master cylinder service
Electrical System:
Complete wiring diagrams, fuse box layout, relay functions, battery and charging system, starter, alternator, lighting systems, horn, wipers, power windows/locks/seats
Body And Chassis:
Body panel repair, door mechanisms, hood/trunk operation, interior trim, underbody protection, rust prevention
HVAC:
Climate control system, A/C compressor, refrigerant system, heater core, blower motor, control panels
Fuel System:
Fuel pump, fuel filter, fuel injectors, fuel tank, fuel pressure regulator, EVAP system
Exhaust System:
Catalytic converter, muffler, exhaust pipes, oxygen sensors
Preventive Maintenance:
Oil changes, filter replacements, coolant flushes, brake fluid service, spark plug replacement, belt inspection/replacement
Troubleshooting:
Diagnostic flowcharts, symptom-based troubleshooting, fault code interpretation (where applicable)
Repair Procedures:
Step-by-step repair instructions for all major components and systems
Diagnostic Procedures:
Engine timing checks, compression tests, fuel pressure testing, electrical system diagnostics
Alignment And Balancing:
Wheel alignment specifications and procedures, wheel balancing
Component Replacement:
Detailed instructions for replacing common wear items and major assemblies
Depth:
Factory-level detail, suitable for professional technicians and advanced DIY enthusiasts
Diagnostic Capabilities:
Extensive, including electrical schematics and diagnostic trees
Rebuild Specifications:
Includes critical torque specifications, clearances, and tolerances for engine and transmission rebuilds
520I Engine:
M50B20 (2.0L Inline-6)
525I Engine:
M50B25 (2.5L Inline-6)
535I Engine:
M30B35 (3.5L Inline-6)
520I Horsepower:
150 PS (148 hp; 110 kW) @ 6000 rpm (M50)
525I Horsepower:
192 PS (189 hp; 141 kW) @ 5800 rpm (M50)
535I Horsepower:
208 PS (205 hp; 153 kW) @ 5700 rpm (M30)
520I Torque:
190 Nm (140 lb-ft) @ 4300 rpm (M50)
525I Torque:
245 Nm (181 lb-ft) @ 4200 rpm (M50)
535I Torque:
305 Nm (225 lb-ft) @ 4000 rpm (M30)
Fuel Injection System:
Bosch Motronic Electronic Fuel Injection (EFI)
Fuel Type:
Unleaded Gasoline (RON 95 / 98 recommended)
Configuration:
Inline 6-cylinder, DOHC (M50) or SOHC (M30)
Bore X Stroke 520I:
80.0 mm x 66.0 mm (M50B20)
Bore X Stroke 525I:
84.0 mm x 75.0 mm (M50B25)
Bore X Stroke 535I:
92.0 mm x 86.0 mm (M30B35)
Compression Ratio 520I:
8.8:1 (M50B20)
Compression Ratio 525I:
10.0:1 (M50B25)
Compression Ratio 535I:
8.0:1 (M30B35)
520I Transmission:
5-speed Manual (Getrag 260/5, later possibly Getrag 260/6 on some markets)
525I Transmission:
5-speed Manual (Getrag 260/5 or Getrag 260/6)
Optional Transmission:
4-speed Automatic (ZF 4HP22 or ZF 4HP24)
Manual Gear Ratios 525I Example:
1st: 4.215, 2nd: 2.195, 3rd: 1.421, 4th: 1.000, 5th: 0.812 (approximate, varies by specific gearbox)
Automatic Features:
Electronic control (later models), sport mode (selector lever).
Manual Transmission Fluid:
BMW MTF LT-2 (or equivalent API GL-4 75W-90 gear oil)
Automatic Transmission Fluid:
BMW ATF LT 71141 (or equivalent Dexron III/Mercon equivalent)
Length:
Approx. 4710-4720 mm (185.4-185.8 in)
Width:
Approx. 1750 mm (68.9 in)
Height:
Approx. 1410-1420 mm (55.5-55.9 in)
Wheelbase:
Approx. 2790-2830 mm (109.8-111.4 in)
Curb Weight 520I:
Approx. 1400-1500 kg (3086-3307 lbs)
Curb Weight 525I:
Approx. 1450-1550 kg (3197-3417 lbs)
Curb Weight 535I:
Approx. 1550-1650 kg (3417-3638 lbs)
Trunk Volume:
Approx. 460-500 liters (16.2-17.7 cu ft)
Era Specific Ratings:
Modern crash test data is limited for this era; relied on passive safety features of the time.
ABS:
Standard on most models, optional on early E34s
Traction Control:
Optional (ASC/ASC+T on later models)
Airbags:
Driver's airbag standard from 1990 onwards, passenger airbag optional.
Seatbelts:
Front and rear seat belts with pretensioners for front occupants
Body Structure:
Reinforced safety cage, crumple zones, side impact protection beams
Oil Change Interval:
Every 7,500 - 10,000 miles (12,000 - 15,000 km) or annually, whichever comes first (depending on driving conditions and oil used).
Spark Plug Replacement:
Approx. 30,000 miles (48,000 km) for standard spark plugs; longer for platinum/iridium plugs (if applicable in later production).
Coolant Flush:
Every 2 years or 30,000 miles (48,000 km).
Brake Fluid Flush:
Every 2 years, regardless of mileage.
Engine Oil Capacity 520I 525I:
Approx. 5.7 - 6.0 liters (6.0 - 6.3 US qt) with filter (M50 engine)
Engine Oil Capacity 535I:
Approx. 6.5 liters (6.9 US qt) with filter (M30 engine)
Engine Oil Viscosity Recommendation:
SAE 15W-40 or 10W-40 (depending on climate); 5W-30/5W-40 for colder regions.
Coolant:
BMW Blue Antifreeze (G48 ethylene glycol based) or equivalent, mixed 50/50 with distilled water.
Cooling System Weaknesses:
Plastic coolant expansion tanks can become brittle and crack; water pump impeller can degrade (especially earlier M30 engines).
Vanos Issues M50:
Variable valve timing (VANOS) system can develop issues with solenoids or seals leading to rough idle or loss of power (on later M50 engines).
Oil Leaks:
Valve cover gaskets, oil pan gaskets, and front/rear main seals are common sources of leaks due to age and material degradation.
Suspension Wear:
Control arm bushings, ball joints, and tie rod ends are common wear items that can lead to alignment issues and poor handling.
Electrical Gremlins:
aging wiring harness, faulty relays, and corroded connectors can lead to intermittent electrical issues.
Bmw Heritage:
BMW's long-standing reputation for building driver-oriented, high-quality automobiles with a focus on performance and engineering.
E34 Introduction:
Introduced in 1987 (as a 1988 model year in North America), the E34 was the successor to the E28 5 Series.
E34 Design Highlights:
Designed by Ercole Spada, it featured a more aerodynamic and refined design compared to its predecessor, with a smoother silhouette and integrated bumpers.
E34 Engine Lineup Evolution:
Initial models used the M20 and M30 engines, with the introduction of the advanced M50 DOHC inline-six engine for the 520i and 525i in 1990.
Production Years:
1987-1996 (globally)
Production Facelift:
Minor facelift in 1993 (e.g., new kidney grille, updated bumpers, side skirts).
