Era Positioning:
The E28 5 Series represented BMW's 'executive' sedan offering in the 1980s, known for its blend of performance, luxury, and engineering.
Target Audience:
Enthusiasts, owners, and independent mechanics seeking to maintain, repair, or restore their E28 525i.
Competitors:
Mercedes-Benz W124 E-Class, Audi 100/200, Volvo 240/700 series, Cadillac Sedan de Ville.
Vehicle Strengths:
Excellent handling, powerful inline-six engines, robust build quality, driver-focused interior, classic BMW design.
Manual Value Proposition:
Provides in-depth, authoritative information essential for preserving the longevity and performance of a classic BMW.
Engine Mechanical:
Complete engine overhaul, cylinder head, block, pistons, crankshaft, camshafts, valve train, timing systems, lubrication, cooling.
Engine Management:
Fuel injection (Bosch Motronic), ignition systems, sensors, actuators, troubleshooting diagnostics.
Transmission:
Manual and automatic transmission service, rebuild procedures, clutch, torque converter, shift mechanisms, fluid specifications.
Drivetrain:
Driveshafts, CV joints, differential, rear axle assembly, wheel bearings.
Suspension:
Front and rear suspension components, shock absorbers, struts, springs, control arms, bushings, alignment specifications.
Steering:
Steering rack, power steering system, steering column, tie rods, troubleshooting.
Brakes:
Front and rear brake systems (disc brakes), ABS (if equipped), master cylinder, calipers, pads, rotors, brake lines, bleeding procedures.
Electrical System:
Battery, charging system (alternator), starting system (starter motor), lighting, horns, wipers, power windows, fuse box, relays.
Bodywork And Chassis:
Body panel repair, interior trim, doors, windows, locks, body sealing, structural integrity, rust prevention and repair.
HVAC:
Heating, ventilation, and air conditioning system diagnosis and repair, refrigerant, components.
Routine Maintenance:
Oil changes, filter replacements, fluid checks and top-offs, spark plug replacement, belt inspections.
Diagnostic Procedures:
Troubleshooting guides for common problems, symptom-based diagnosis, diagnostic trouble codes (DTCs) for relevant systems.
Repair Procedures:
Step-by-step instructions for component removal, installation, adjustment, and repair for all covered systems.
Rebuilding Procedures:
Detailed instructions for engine and transmission rebuilds, including part specifications and clearances.
Restoration Guidance:
Information valuable for restoring the vehicle, including original specifications and potential sourcing of parts.
Depth:
Comprehensive (covers everything from basic maintenance to full rebuilds and diagnostics).
Detail Level:
High (includes detailed diagrams, torque specifications, clearances, and part numbers where applicable).
Engine Type:
Inline-Six Cylinder, Naturally Aspirated
Displacement:
2.5 Liters (approx. 2494 cc)
Bore X Stroke:
84.0 mm x 75.0 mm (typical for M30B25)
Compression Ratio:
Typically 8.5:1 or 9.0:1 depending on variant
Valve Train:
SOHC (Single Overhead Camshaft), 2 valves per cylinder
Horsepower:
Approx. 150-170 hp (varies slightly by market and specific engine tune)
Torque:
Approx. 160-175 lb-ft (varies slightly by market and specific engine tune)
Injection System:
Bosch L-Jetronic or Motronic (fuel injection)
Fuel Type:
Unleaded gasoline (Premium Octane recommended)
Coolant Type:
BMW recommended coolant (typically a silicate-free ethylene glycol based coolant) mixed 50/50 with distilled water.
Oil Type:
API SF or SG, SAE 20W-50 or 15W-40 (refer to manual for precise specification and seasonal recommendations)
Oil Capacity:
Approx. 6.0 - 6.5 Liters (6.3 - 6.9 US Quarts) with filter change.
Type:
4-speed Manual Transmission (Getrag 265 common)
Type:
3-speed or 4-speed Automatic Transmission (ZF 4HP22 common)
Manual Gear Ratios:
Specific ratios are available in the manual, e.g., 1st: 3.72, 2nd: 2.40, 3rd: 1.57, 4th: 1.00, R: 3.15 (example, consult manual for exact ratios).
Manual Transmission Fluid:
GL-4 or GL-5 Hypoid Gear Oil, SAE 75W-90 or 80W-90 (refer to manual for exact specification).
Automatic Transmission Fluid:
Dexron II or equivalent (refer to manual for exact specification).
Radio:
Factory installed AM/FM stereo with cassette player, often with Nakamichi or Blaupunkt options.
On Board Computer:
Optional On-Board Computer (OBC) with features like MPG, range, and basic diagnostics.
Cruise Control:
Standard or optional cruise control system.
Early Features:
Power windows, power door locks, central locking, power mirrors, heated mirrors, optional power antenna, sunroof.
Oil Change Interval:
Every 7,500 to 10,000 miles or annually (refer to manual for specific conditions and year).
Transmission Fluid Change:
Manual: Every 60,000 miles or as per manual. Automatic: Every 30,000-50,000 miles (severe use may require more frequent changes).
Coolant Flush:
Every 2 years or 30,000 miles.
Spark Plug Replacement:
Every 30,000 miles (recommend checking manual for specific plug type and gap).
Brake Fluid:
DOT 3 or DOT 4 (consult manual for exact specification and change interval).
Power Steering Fluid:
Dexron II or equivalent (BMW specific PSF might be recommended).
Common Problems:
Cooling system leaks (hoses, water pump, radiator), vacuum leaks, fuel injector issues, worn suspension bushings, seized heater control valves, instrument cluster failures.
Electrical Quirks:
Corroded wiring connectors, failing relays, OBC (On-Board Computer) malfunctions.
Bmw Legacy:
BMW's reputation for building driver-focused, high-performance sedans with a focus on engineering and quality.
E28 Introduction:
Launched in 1981 as the successor to the E12 5 Series, the E28 introduced updated styling, improved aerodynamics, and updated mechanicals.
E28 Major Updates:
Introduction of Motronic fuel injection, available ABS, and updated engine options throughout its production run.
Production Years:
1981-1988
Manufacturing Locations:
Germany (primarily Dingolfing plant)
