1988-1990 - E34 early
Early 520i used the M20B20 single-cam inline-six in many markets.
Vehicle database
BMW 5 Series
E34 / 1988-1996 / Executive sedan/touring
EuropeUnited KingdomMiddle Eastselected global marketsCoverage: expanded
Year and generation map
1990-1992 - E34 M50 transition
520i moved to the M50B20 24-valve inline-six in many European-market cars.
1992-1996 - E34 VANOS update
520i received the M50B20TU with VANOS depending on production date and market.
Year and trim selector
Choose the exact year and trim to see engine, oil and service details.
Engine codes by year
| Year | Trim | Engine codes | Displacement | Fuel system |
|---|---|---|---|---|
| 1991 | 520i | M50B20 | 1991 cc | Bosch electronic fuel injection |
Oil capacity by engine
| Year | Engine codes | Oil type | Oil capacity | Fluid |
|---|---|---|---|---|
| 1991 | M50B20 | 5W-40, 5W-30 or 10W-40 depending on climate; use oil with suitable BMW approval for older petrol engines. | 5.75 L service fill with filter commonly listed for 1990-1991 E34 520i M50B20. | Gearbox-code-specific manual fluid or automatic ATF; do not choose fluid by model name alone. |
Engine codes and variants
M20B20 - 2.0L SOHC inline-6
1988-1990 / 1991 cc / Gasoline / Naturally aspirated
- Oil type
- 15W-40, 10W-40 or climate-appropriate classic BMW petrol oil; verify owner manual.
- Oil capacity
- Approximately 4.25-4.5 L with filter depending on specification.
- Related diagnostic codes
- P0300, P0171, P0115
On M20 engines, timing belt history is more important than mileage claims.
Common failure patterns
Timing belt service neglectVacuum leaksDistributor/ignition wearCooling system age
M50B20 - 2.0L DOHC 24-valve inline-6
1990-1992 / 1991 cc / Gasoline / Naturally aspirated
- Oil type
- 5W-40, 5W-30 or 10W-40 depending on climate and oil approval.
- Oil capacity
- 5.75 L service fill with filter commonly listed for E34 520i M50B20.
- Spark plug interval
- Inspect around 30k-40k km; replace earlier for misfire or rough idle.
- Related diagnostic codes
- P0300, P0301, P0171, P0115, P0130
1991 520i is commonly M50B20 in European-market cars, but production month and market should be checked.
Common failure patterns
Vacuum leaksValve cover oil leaksIgnition coil/boot faultsCooling system plastic aging
M50B20TU - 2.0L DOHC VANOS inline-6
1992-1996 / 1991 cc / Gasoline / Naturally aspirated
- Oil type
- 5W-40, 5W-30 or 10W-40 depending on climate and oil approval.
- Oil capacity
- 5.75 L service fill with filter commonly listed for E34 520i M50-family engines.
- Related diagnostic codes
- P0300, P0171, P0505
TU engines add VANOS; idle and low-rpm torque complaints should include VANOS and vacuum checks.
Common failure patterns
VANOS seal wear symptomsVacuum leaksRough idleCooling system age
Transmission variants
Getrag/ZF 5-speed manual family - 5-speed manual
1988-1996 / Manual
- Fluid
- Use gearbox-code-specific manual transmission fluid; verify label/tag before service.
- Service note
- On older BMWs, service by actual gearbox tag rather than model name alone.
- Related diagnostic codes
Common failure patterns
Shifter bushing wearClutch hydraulic leaksGear oil age
ZF 4HP22 / 5HP18 family by engine and year - Automatic transmission
1988-1996 / Torque-converter automatic
- Fluid
- ATF specification depends on transmission tag and market.
- Service note
- Confirm exact automatic gearbox before selecting fluid.
- Related diagnostic codes
- P0700, P0715
Common failure patterns
Delayed engagement when neglectedValve body wearFluid leak from old seals
Technical specifications
- Engines: M20B20 2.0L I6, M50B20 2.0L 24V I6, M50B20TU 2.0L VANOS I6, M50B25 2.5L I6, M30/M60/S38 variants by model
- Transmissions: 5-speed manual, 4-speed automatic, 5-speed automatic on selected later models
- Tire sizes: 195/65R15, 205/65R15, 225/60R15, 225/55R16
- Bolt pattern: 5x120
- Wheel torque: 120 Nm typical for BMW 5 Series E34 wheel bolts; verify wheel type.
- Battery: Large European DIN battery; capacity varies by engine and equipment.
Fluids and service data
- Engine oil: Depends on engine and climate. 1991 520i M50B20 commonly uses 5W-40, 5W-30 or 10W-40 oil meeting suitable BMW approval for older petrol engines.
- Transmission fluid: Manual or automatic fluid depends on gearbox code; verify ZF/Getrag transmission tag before service.
- Coolant: BMW-compatible phosphate/nitrite-free coolant mixed with demineralized water.
- Brake fluid: DOT 4 brake fluid.
Maintenance schedule focus
Engine oil and filter
Every 10k-12k km or annually for conservative use
Older M50 engines benefit from conservative oil intervals and correct filter quality.
Related: P0011, P0300
Cooling system
Inspect every service; refresh aging plastic/rubber parts proactively
Overheating can damage inline-six engines quickly.
Related: P0115, P0128
Ignition and vacuum inspection
Inspect when idle, misfire or fuel-trim symptoms appear
Vacuum leaks and old ignition parts are common causes of poor running.
Related: P0300, P0171
Known problems
Cooling system aging
highAffected years: 1988-1996 E34
Symptoms
Coolant smellTemperature riseHeater output changes
First checks
Radiator necksWater pumpThermostatExpansion tank capHoses
Related: P0115, P0128
M50 rough idle and lean running
moderateAffected years: 1990-1996 M50-family 520i/525i
Symptoms
Rough idleHesitationLean mixture symptoms
First checks
Intake bootsVacuum hosesICVMAF dataIgnition coils
Related: P0171, P0300, P0505