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).
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.
Start here
What do you need to know?
This page covers the whole 1984 Mercedes-Benz S-Class model year. Choose your task first; exact trims and engines are separated where the factory offered different versions.
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.
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.
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
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
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
No factory configuration matches those filters.
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
- Factory intervals
- 8
- Fitment-scoped
- 9
- Exact references
- 2
Before orderingIdentify 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 filter
Sourced interval available
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 plugs
Sourced interval available
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 filter
Sourced interval available
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 fluid
Sourced interval available
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 element
Exact reference available
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
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
- Service replacementK&N E-2872
Qty. 1 · Reusable engine air-filter element · catalog-listed
K&N lists one element for this application; confirm VIN and build date before ordering.
Catalog: K&N Engineering — 2017 European Automotive Catalog, S-Class application tables (archived copy) · W126 S-Class table — 380 SE, 1984 — E-2872 · checked
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500 SEL — 5.0-liter M117 fuel-injected V8
K&N E-2872
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
- Service replacementK&N E-2872
Qty. 1 · Reusable engine air-filter element · catalog-listed
K&N lists one element for this application; confirm VIN and build date before ordering.
Catalog: K&N Engineering — 2017 European Automotive Catalog, S-Class application tables (archived copy) · W126 S-Class table — 500 SEL, 1984 — E-2872 · checked
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Fuel filter
Sourced interval available
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 sensor
Sourced interval available
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 coolant
Sourced interval available
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 filter
Exact reference available
Use the exact engine, VIN, and build date to confirm the catalogued service part before ordering.
300 SD — 3.0-liter OM617 turbocharged diesel inline-five
MAHLE OX 78D
Source: MAHLE Aftermarket — Mercedes-Benz passenger-car filter application catalog · 1984 Mercedes-Benz 300SD 3.0L L5 — OX 78D · checked
Verified ordering references
- Service replacementMAHLE OX 78D
Qty. 1 · Engine oil-filter element · catalog-listed
Manufacturer-catalogued application; confirm VIN and build date before ordering.
Catalog: MAHLE Aftermarket — Mercedes-Benz passenger-car filter application catalog · 1984 Mercedes-Benz 300SD 3.0L L5 — OX 78D · checked
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Sources
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