E34 Generation Segment:
Mid-size executive sedan (often referred to as the 'Baby Shark' or 'Big Shark' by enthusiasts due to its distinct grille design compared to predecessors).
Key Competitors:
Mercedes-Benz W124 E-Class, Audi V8 Quattro, Jaguar XJ, Volvo 740/940 series, Lexus LS400 (later in the E34's life).
E34 Selling Points:
Renowned BMW driving dynamics, robust build quality, sophisticated engineering for its era, availability of various engine options including inline-sixes known for smoothness and power delivery, comfortable ride, classic BMW design.
Target Audience:
BMW E34 owners, independent repair shops, DIY enthusiasts looking for in-depth technical information.
Engine Systems:
Engine mechanicals (cylinder head, block, pistons, crankshaft, camshafts), lubrication system, cooling system, fuel system (injection, sensors, pumps), ignition system (coils, DME control), exhaust system, emissions control systems.
Transmission Systems:
Manual transmission (clutch, gearbox, driveshafts), Automatic transmission (hydraulic control, torque converter, valve body, electronics - specify based on typical E34 options).
Chassis Systems:
Suspension (front struts, rear multi-link, shock absorbers, springs), steering system (power steering pump, rack and pinion, steering column), braking system (ABS, brake hydraulics, discs, pads, calipers).
Electrical Systems:
Wiring diagrams, fuse box layouts, lighting systems, starting and charging system, instrument cluster, HVAC controls, power windows/locks/mirrors, diagnostic connectors (OBD I), ECU functions.
Body And Interior:
Body panel removal and installation, door mechanisms, interior trim, seat adjustments, glass replacement, seals, bumpers.
Routine Maintenance:
Oil changes, filter replacements (oil, air, fuel), spark plug replacement, coolant flushes, brake fluid changes, belt inspections and replacement, tire rotations, battery checks.
Major Repairs:
Engine rebuilds (e.g., head gasket, valve seals), transmission overhaul, suspension component replacement (ball joints, control arms), brake system repairs (caliper rebuild, master cylinder replacement), fuel injector servicing, differential service.
Diagnostics And Troubleshooting:
Fault code interpretation (where applicable for OBD I), symptom-based troubleshooting guides, electrical system diagnostics (continuity, voltage checks), fuel pressure testing, ignition timing checks.
Special Procedures:
Timing belt replacement (if applicable to specific engine variant), calibration of sensors, bleeding of hydraulic systems, removal/installation of specific complex components.
Diagnostic Complexity:
Advanced diagnostics including electrical tracing and component testing, not just basic checks.
Repair Scope:
Full vehicle repair, from minor adjustments to major overhauls and component replacements.
Detail Level:
Detailed step-by-step instructions with accompanying photographic or diagrammatic illustrations.
Engine Model E34 520I:
Primarily BMW M50B20TU (2.0L Inline-6, Double VANOS for later models within this range, potentially M20B20 for very early production or specific markets, but M50 is dominant for this period).
Horsepower M50B20:
Approx. 150 PS (148 hp; 110 kW) at 5,900 rpm (figures may vary slightly by market and specific engine variant within the early E34 lifecycle).
Torque M50B20:
Approx. 190 Nm (140 lb-ft) at 4,200 rpm (figures may vary).
Fuel Delivery:
Bosch Motronic Electronic Fuel Injection (EFI) with multi-point injection (MPI).
Bore Stroke M50B20:
80.0 mm x 66.0 mm
Compression Ratio M50B20:
10.0:1
Engine Layout:
Inline 6-cylinder, DOHC (Double Overhead Camshafts), 24 valves.
Standard Transmission Type:
5-speed Manual Transmission (e.g., Getrag 260/5)
Optional Transmission Type:
4-speed Automatic Transmission (e.g., ZF 4HP-22)
Automatic Transmission Control:
Electronic Control Unit (ECU) for shift logic, offering comfort and sport modes on some variants.
Length:
Approx. 4,720 mm (185.8 in)
Width:
Approx. 1,751 mm (68.9 in)
Height:
Approx. 1,412 mm (55.6 in)
Curb Weight Approx:
1,500 - 1,600 kg (3,307 - 3,527 lb), depending on transmission and options.
Crash Test Era Standards:
Designed to meet European and North American safety standards of the late 1980s/early 1990s. Specific official ratings from NCAP for this era are less common than modern tests.
Active Safety Systems:
Optional Anti-lock Braking System (ABS), advanced chassis tuning for stability, power-assisted steering.
Passive Safety Features:
Reinforced passenger cell, crumple zones, driver's airbag (often optional or standard on later models/specific markets), seatbelt pre-tensioners (on some models).
Oil Change Interval Typical:
Every 10,000 - 15,000 km (6,000 - 9,000 miles) or 12 months, whichever comes first, depending on driving conditions and oil type used.
Spark Plug Replacement Interval:
Typically every 40,000 - 60,000 km (25,000 - 37,000 miles) for standard plugs, or longer for platinum/iridium plugs if fitted.
Engine Oil Specification:
API SG/SH, ACEA A2/A3; Viscosity: 5W-30, 5W-40, 10W-40, 10W-50 depending on climate. BMW Longlife-98 or similar synthetic recommended.
Coolant Specification:
Ethylene glycol based coolant, mixed 50/50 with distilled water. BMW Part No. 83 51 9 400 327 (or equivalent from reputable brands like Prestone or Castrol).
Brake Fluid Specification:
DOT 3 or DOT 4.
Transmission Fluid Manual:
Gear oil API GL-4 or GL-5, SAE 75W-90 or 80W-90. BMW MTF LT-2 for later variants if applicable.
Transmission Fluid Automatic:
ATF Dexron III or equivalent (e.g., ZF Lifeguardfluid 5 for ZF 4HP-22 applications).
Common E34 Issues:
Cooling system component degradation (radiator, hoses, water pump), VANOS seal failure (on M50 engines), oil pan gasket leaks, valve cover gasket leaks, OVP relay failure (power supply issues), ABS sensor failures, fuel pump issues, door seal degradation, seized sunroof mechanisms.
