Car Model History

Second generation · W126 · 1981–1991

1984Mercedes-Benz S-Class

The best-selling classic S-Class and a design icon. It reached US showrooms for 1981 (late-1980 launch). The first production car offered with a driver's airbag; later added a passenger airbag (1988). Also spawned the C126 coupe (SEC).

Second generation · W126

1984 Mercedes-Benz S-Class (W126) — sedan, front three-quarter view

Photo: “1984 Mercedes-Benz 280 SE (9040669511)” by Niels de Wit from Lunteren, The Netherlands / Wikimedia Commons, licensed under CC BY 2.0. Cropped to 16:9.

The 1984 model year

Overview

For 1984, the U.S. W126 roster changed to three sedans: the 300 SD turbodiesel, short-wheelbase 380 SE V8, and long-wheelbase 500 SEL V8. The 500 SEL brought the 5.0-liter M117 to the regular U.S. S-Class table while the SE added a short-wheelbase gasoline choice.

Specifications

Engines
  • 3.0-liter OM617 turbocharged diesel inline-five
  • 3.8-liter M116 fuel-injected V8
  • 5.0-liter M117 fuel-injected V8
Transmissions
4-speed automatic
Body styles
Four-door rear-wheel-drive luxury sedan, Four-door long-wheelbase rear-wheel-drive luxury sedan

Year over year

What changed

  • The 380 SEL left the sourced U.S. roster and the short-wheelbase 380 SE took its place.
  • The long-wheelbase 500 SEL joined as the larger gasoline flagship above the 380 SE.

Worth knowing

Notable

  • Wheelbase and engine are both material: 380 SE and 500 SEL are not interchangeable trim labels.

Living with it

Reliability & ownership notes

  • Confirm the chassis, engine number, market specification, and build date before ordering parts; U.S. model-year rosters do not describe gray-market or other-market W126 sedans.
  • Use the maintenance record scoped to the exact engine shown on this page; it must not be projected onto the diesel, coupe, or other W126 powertrains that the source does not cover.

Maintenance & service parts

Keep your 1984 S-Class on the road

Start with the service interval, then match the engine or exact version you own. Order links appear only when a catalog-backed part number is available, and every listing still needs a fitment check.

Service desk

What this car needs & when

Use this as a service-planning checklist for 1984 Mercedes-Benz S-Class. Start with the interval, confirm which engine or configuration you have, then use an exact ordering reference when one is verified.

Service topics
9
Scheduled topics
8
Applicability stated
9
Exact references
2

Before ordering Identify your engine, options and build date. Part numbers and sizes can change within one model year. Shopping links appear only for catalog-backed references; still verify the listing against your vehicle before ordering.

  • Engine oil and filterView intervals, applicability and sources

    Engine oil and filter

    Sourced interval available

    Applies to: 1984 · M117.963 5.0L V8 · 500 SEL sedan (126.037) · United States · Exact 1984 500 SEL factory record; other gasoline engines, diesel, SEC, and other W126 configurations are not claimed.

    Published interval: 7,500 mi / 12,000 km / 12 months · Normal service; at least annually with year-round multigrade oil.

    Source: Mercedes-Benz — 1984 500 SEL (W126) mileage schedule, preserved by Operation CHARM · Normal Service — 7,500-mile row and repeating 7,500-mile rows · checked

  • Spark plugsView intervals, applicability and sources

    Spark plugs

    Sourced interval available

    Applies to: 1984 · M117.963 5.0L V8 · 500 SEL sedan (126.037) · United States · Exact 1984 500 SEL factory record; other gasoline engines, diesel, SEC, and other W126 configurations are not claimed.

    Published interval: 30,000 mi / 48,000 km · Normal-service replacement interval.

    Source: Mercedes-Benz — 1984 500 SEL (W126) mileage schedule, preserved by Operation CHARM · Normal Service — repeating 30,000-mile replacement rows · checked

  • Automatic-transmission fluid and filterView intervals, applicability and sources

    Automatic-transmission fluid and filter

    Sourced interval available

    Applies to: 1984 · M117.963 5.0L V8 · 500 SEL sedan (126.037) · United States · Exact 1984 500 SEL factory record; other gasoline engines, diesel, SEC, and other W126 configurations are not claimed.

    Published interval: 30,000 mi / 48,000 km · Normal-service replacement interval.

    Source: Mercedes-Benz — 1984 500 SEL (W126) mileage schedule, preserved by Operation CHARM · Normal Service — repeating 30,000-mile fluid/filter replacement rows · checked

  • Brake fluidView intervals, applicability and sources

    Brake fluid

    Sourced interval available

    Applies to: 1984 · M117.963 5.0L V8 · 500 SEL sedan (126.037) · United States · Exact 1984 500 SEL factory record; other gasoline engines, diesel, SEC, and other W126 configurations are not claimed.

    Published interval: 30,000 mi / 48,000 km · Normal-service replacement interval in the archived mileage schedule.

    Source: Mercedes-Benz — 1984 500 SEL (W126) mileage schedule, preserved by Operation CHARM · Normal Service — repeating 30,000-mile replacement rows · checked

  • Engine air-filter elementView intervals, applicability and sources

    Engine air-filter element

    Exact reference available

    Applies to: 1984 · M117.963 5.0L V8 · 500 SEL sedan (126.037) · United States · Exact 1984 500 SEL factory record; other gasoline engines, diesel, SEC, and other W126 configurations are not claimed.

    Published interval: 30,000 mi / 48,000 km · Normal-service replacement interval.

    Source: Mercedes-Benz — 1984 500 SEL (W126) mileage schedule, preserved by Operation CHARM · Normal Service — repeating 30,000-mile replacement rows · checked

    380 SE — 3.8-liter M116 fuel-injected V8

    K&N E-2872

    Applies to: 1984 · 3.8-liter M116 fuel-injected V8 · 380 SE · Exact 1984 380 SE engine application. Confirm VIN and build date before ordering.

    Source: K&N Engineering — 2017 European Automotive Catalog, S-Class application tables (archived copy) · W126 S-Class table — 380 SE, 1984 — E-2872 · checked

    Verified ordering references

    500 SEL — 5.0-liter M117 fuel-injected V8

    K&N E-2872

    Applies to: 1984 · 5.0-liter M117 fuel-injected V8 · 500 SEL · Exact 1984 500 SEL engine application. Confirm VIN and build date before ordering.

    Source: K&N Engineering — 2017 European Automotive Catalog, S-Class application tables (archived copy) · W126 S-Class table — 500 SEL, 1984 — E-2872 · checked

    Verified ordering references

  • Fuel filterView intervals, applicability and sources

    Fuel filter

    Sourced interval available

    Applies to: 1984 · M117.963 5.0L V8 · 500 SEL sedan (126.037) · United States · Exact 1984 500 SEL factory record; other gasoline engines, diesel, SEC, and other W126 configurations are not claimed.

    Published interval: 60,000 mi / 96,000 km · Normal-service replacement interval.

    Source: Mercedes-Benz — 1984 500 SEL (W126) mileage schedule, preserved by Operation CHARM · Normal Service — 60,000- and 120,000-mile replacement rows · checked

  • Oxygen sensorView intervals, applicability and sources

    Oxygen sensor

    Sourced interval available

    Applies to: 1984 · M117.963 5.0L V8 · 500 SEL sedan (126.037) · United States · Exact 1984 500 SEL factory record; other gasoline engines, diesel, SEC, and other W126 configurations are not claimed.

    Published interval: 60,000 mi / 96,000 km · Normal-service replacement interval.

    Source: Mercedes-Benz — 1984 500 SEL (W126) mileage schedule, preserved by Operation CHARM · Normal Service — 60,000- and 120,000-mile replacement rows · checked

  • Engine coolantView intervals, applicability and sources

    Engine coolant

    Sourced interval available

    Applies to: 1984 · M117.963 5.0L V8 · 500 SEL sedan (126.037) · United States · Exact 1984 500 SEL factory record; other gasoline engines, diesel, SEC, and other W126 configurations are not claimed.

    Published interval: 90,000 mi / 144,000 km · Replacement row; earlier 30,000- and 60,000-mile rows call only for inspection.

    Source: Mercedes-Benz — 1984 500 SEL (W126) mileage schedule, preserved by Operation CHARM · Normal Service — 90,000-mile coolant replacement row; 30,000/60,000 rows distinguished as inspect only · checked

  • Engine oil filterView intervals, applicability and sources

    Engine oil filter

    Exact reference available

    Use the exact engine, VIN, and build date to confirm the catalogued service part before ordering.

    Applies to: 1984

    300 SD — 3.0-liter OM617 turbocharged diesel inline-five

    MAHLE OX 78D

    Applies to: 1984 · 3.0-liter OM617 turbocharged diesel inline-five · 300 SD · Exact 1984 300 SD engine application. Confirm VIN and build date before ordering.

    Source: MAHLE Aftermarket — Mercedes-Benz passenger-car filter application catalog · 1984 Mercedes-Benz 300SD 3.0L L5 — OX 78D · checked

    Verified ordering references

Collect

Bring this model year home

Find a scale model using the exact year, make, and model—not a generic generation search.

Sources

  1. Mercedes-Benz Media — factory S-Class history and W126 design/safety chronology
  2. Mercedes-Benz Club of America — 1981–1991 W126 U.S.-market buyer's guide

Other Second generation years

Explore the W126 generation →All Second generation · W126 years →

Complete, source-verified lineup

Find your exact 1984 S-Class

Start with a family, body style, or engine. Every card opens the facts and maintenance information for that factory version.

3factory configurations
Verified complete for the U.S.-marketHow this lineup was verified

We checked this U.S.-market lineup against period sources for factory sedan, coupe, cabriolet, drivetrain, and powertrain roster represented by the cited exact-year or factory-archive evidence. Every version shown below has its own detail page.

Verified 2026-09-01 from Mercedes-Benz Club of America — 1981–1991 W126 U.S.-market buyer's guide.

3versions shown
Browse 3 documented records — use the filters above to narrow the list
Four-door rear-wheel-drive luxury sedan

Mercedes-Benz 300 SD Automatic

Body
Four-door rear-wheel-drive luxury sedan
Engine
3.0-liter OM617 turbocharged diesel inline-five
Gearbox
4-speed automatic
Built
Regular production
Open exact version
Four-door rear-wheel-drive luxury sedan

Mercedes-Benz 380 SE Automatic

Body
Four-door rear-wheel-drive luxury sedan
Engine
3.8-liter M116 fuel-injected V8
Gearbox
4-speed automatic
Built
Regular production
Open exact version
Four-door long-wheelbase rear-wheel-drive luxury sedan

Mercedes-Benz 500 SEL Automatic

Body
Four-door long-wheelbase rear-wheel-drive luxury sedan
Engine
5.0-liter M117 fuel-injected V8
Gearbox
4-speed automatic
Built
Regular production
Open exact version

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