Car Model History

First generation · E21 · 1977–1983

1978BMW 3 Series

The original 3 Series — a two-door sport sedan that replaced the 02 Series (the 2002). US cars arrived for 1977; the E21 established the compact rear-drive BMW formula the line still follows.

First generation · E21

1978 BMW 3 Series E21 320/6 Baur TC1, front three-quarter view

Photo: “BMW E21 320-6 Baur TC1 1978-1979 .jpg” by Michel-TC1 / Wikimedia Commons, licensed under CC BY-SA 4.0. Cropped to 16:9.

Quick facts

Engines
1offered2.0L fuel-injected M10 inline-four
Top output
110hp2.0L fuel-injected M10 inline-four

Body stylesTwo-door sedan

Start here

What do you need to know?

This page covers the whole 1978 BMW 3 Series 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 1978 3 Series

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

1factory configurations
Verified complete for the U.S.-marketHow this lineup was verified

We checked this U.S.-market lineup against period sources for BMW's complete 1978 U.S. E21 roster: the 2.0-liter two-door 320i. Every version shown below has its own detail page.

Verified 2026-09-01 from BMW of North America — first 3 Series U.S. history and specifications, BMW of North America — new BMW 3 Series Sedan and Sports Wagon technical release.

1versions shown
Two-door sedan

BMW 320i

Body
Two-door sedan
Engine
2.0L fuel-injected M10 inline-four (110 hp / 112 lb-ft)
Gearbox
4-speed Getrag manual or 3-speed ZF automatic
Built
Regular production
Open exact version

The 1978 model year

Overview

For 1978 the U.S. 3 Series remained the two-door 320i with its fuel-injected 2.0-liter M10 four-cylinder, rated at 110 hp and 112 lb-ft. The additional four- and six-cylinder E21 variants sold in Europe were not part of BMW of North America's catalog.

Specifications

Engines
  • 2.0L fuel-injected M10 inline-four110 hp
Body styles
Two-door sedan

Year over year

What changed

  • The single-model U.S. 320i roster continued after the 1977 launch.
  • BMW's European-market six-cylinder expansion did not add a U.S. 323i or 320/6.

Worth knowing

Notable

  • The U.S. catalog remained much narrower than the expanding European E21 range.
  • The 1.8-liter U.S. engine and 320iS had not yet arrived.

Living with it

Reliability & ownership notes

  • Match fuel-injection and engine parts to the 2.0-liter U.S. M10; later 1.8-liter E21 parts are not automatically interchangeable.
  • Rust, cooling-system condition, fuel-system health, and aged electrical connections remain priority inspection areas.

Maintenance & service parts

Keep your 1978 3 Series 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 1978 BMW 3 Series. Start with the interval, confirm which engine or configuration you have, then use an exact ordering reference when one is verified.

Service topics
10
Factory intervals
6
Fitment-scoped
10
Exact references
5

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

    Applies to: 1978 · M10 2.0L fuel-injected inline-four · 320i (E21) · United States · Exact February 1978 E21 factory schedule, applied only to the cataloged US 320i; later model years are not inferred from this issue.

    Published interval: 5,000 mi / 7,500 km · First BMW Oil Service; the published BMW Inspection also renews both items at every 10,000 miles.

    Source: BMW — E21 Maintenance and General Hints workshop manual, February 1978 factory issue (preserved by Bimmer-Service) · Factory manual 00-00/35 and 00-00/37 — 5,000-mile Oil Service and 10,000-mile BMW Inspection · checked

  • BMW Inspection

    Sourced interval available

    A one-time First BMW Inspection is due at 600 miles (1,000 km). The recurring factory list covers 26 engine, driveline, cooling, brake, steering, lighting, restraint, and diagnostic checks or replacements.

    Applies to: 1978 · M10 2.0L fuel-injected inline-four · 320i (E21) · United States · Exact February 1978 E21 factory schedule, applied only to the cataloged US 320i; later model years are not inferred from this issue.

    Published interval: 10,000 mi / 15,000 km · Begin at 10,000 miles and repeat every 10,000 miles.

    Source: BMW — E21 Maintenance and General Hints workshop manual, February 1978 factory issue (preserved by Bimmer-Service) · Factory manual 00-00/23 and 00-00/37 — 600-mile first inspection; recurring BMW Inspection every 15,000 km/10,000 miles · checked

  • Transmission oil

    Sourced interval available

    Applies to: 1978 · M10 2.0L fuel-injected inline-four · 320i (E21) · United States · Exact February 1978 E21 factory schedule, applied only to the cataloged US 320i; later model years are not inferred from this issue.

    Published interval: 20,000 mi / 30,000 km · Change during the BMW Inspection at this interval.

    Source: BMW — E21 Maintenance and General Hints workshop manual, February 1978 factory issue (preserved by Bimmer-Service) · Factory manual 00-00/11 — extra work during BMW Inspection every 30,000 km/20,000 miles · checked

  • Final-drive oil

    Sourced interval available

    Applies to: 1978 · M10 2.0L fuel-injected inline-four · 320i (E21) · United States · Exact February 1978 E21 factory schedule, applied only to the cataloged US 320i; later model years are not inferred from this issue.

    Published interval: 20,000 mi / 30,000 km · Change during the BMW Inspection at this interval.

    Source: BMW — E21 Maintenance and General Hints workshop manual, February 1978 factory issue (preserved by Bimmer-Service) · Factory manual 00-00/11 — extra work during BMW Inspection every 30,000 km/20,000 miles · checked

  • Fuel strainer or fuel filter

    Sourced interval available

    Applies to: 1978 · M10 2.0L fuel-injected inline-four · 320i (E21) · United States · Exact February 1978 E21 factory schedule, applied only to the cataloged US 320i; later model years are not inferred from this issue.

    Published interval: 20,000 mi / 30,000 km · Clean the fuel strainers or renew the fuel filter during the BMW Inspection.

    Source: BMW — E21 Maintenance and General Hints workshop manual, February 1978 factory issue (preserved by Bimmer-Service) · Factory manual 00-00/11 and 00-00/15–16 — 20,000-mile extra-work list and fuel-system procedure · checked

  • Engine air-filter element

    Exact reference available

    BMW 13 72 1 278 138

    Applies to: 1978 · M10 2.0L fuel-injected inline-four · 320i (E21) · United States · Exact February 1978 E21 factory schedule, applied only to the cataloged US 320i; later model years are not inferred from this issue.

    Published interval: 10,000 mi / 15,000 km · Replace at each published BMW Inspection.

    Source: BMW — E21 Maintenance and General Hints workshop manual, February 1978 factory issue (preserved by Bimmer-Service) · Factory manual 00-00/37, item 15 — replacing air-cleaner element · checked

    Verified ordering references

    • Original equipmentBMW 13721278138

      Qty. 1 · Engine air-filter element; current replacement for 13 72 1 261 012 and 13 72 1 271 254 · current

      The exact-year BMW catalog lists the earlier element for cars produced through September 1979 and identifies 13 72 1 278 138 as its current replacement; confirm VIN and installed airbox before ordering.

      Catalog: BMW electronic parts catalog — 1978 320i (E21) intake-silencer and filter-cartridge diagram · Intake silencer / filter cartridge diagram — item 02, production through September 1979 and replacement chain · checked

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  • Front windshield-wiper blade set

    Exact reference available

    BMW 61 61 9 069 195

    Applies to: 1978 · M10 2.0L fuel-injected inline-four · 320i (E21) · United States · Exact 1978 catalog fitment only; this parts record does not establish a replacement interval. Confirm the VIN and installed wiper arms before ordering.

    Source: BMWPartsDeal — exact-year 1978 BMW 320i front-wiper catalog listing · Genuine 1978 BMW 320i Wiper Blade — Front Windshield Wiper Blade Set 61619069195 and supersession list · checked

    Verified ordering references

    • Original equipmentBMW 61619069195

      Qty. 1 · Front · Front windshield-wiper blade set; current replacement for 61 61 1 362 189, 61 61 9 061 906, 61 61 1 365 883, and 61 61 1 365 991 · current

      The 1978-selected catalog lists this complete front set for the E21 320i. Confirm the VIN and installed wiper arms before ordering, especially if the car has been modified.

      Catalog: BMWPartsDeal — exact-year 1978 BMW 320i front-wiper catalog listing · Genuine 1978 BMW 320i Wiper Blade — Front Windshield Wiper Blade Set 61619069195 and supersession list · checked

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  • Air-conditioning compressor belt

    Exact reference available

    BMW 64 55 1 722 991

    Applies to: 1978 · M10 2.0L fuel-injected inline-four · 320i (E21) with air conditioning · United States · Exact 1978 catalog fitment for an air-conditioning-equipped car only; this record does not establish a replacement interval or the separate alternator/water-pump belt. Confirm the VIN, installed compressor drive, and belt routing before ordering.

    Source: BMWPartsDeal — exact-year 1978 BMW 320i drive-belt catalog listing · Genuine 1978 BMW 320i Drive Belt — AC Belt 64551722991 and supersession list · checked

    Verified ordering references

    • Original equipmentBMW 64551722991

      Qty. 1 · Air-conditioning compressor drive · A/C belt; current replacement for 64 52 1 469 234, 64 55 1 469 267, 64 55 1 717 230, 64 55 1 722 990, and 64 52 1 276 096 · current

      Applies only when the car has the cataloged air-conditioning compressor drive; it is not the separate alternator/water-pump belt.

      Catalog: BMWPartsDeal — exact-year 1978 BMW 320i drive-belt catalog listing · Genuine 1978 BMW 320i Drive Belt — AC Belt 64551722991 and supersession list · checked

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  • Front brake pads and rear brake shoes

    Exact reference available

    BMW 34 11 1 159 249 front; 34 21 1 160 165 rear

    Applies to: 1978 · M10 2.0L fuel-injected inline-four · 320i (E21) · United States · Exact 1978 catalog fitment only; replace friction material according to measured wear and hardware condition. Confirm the VIN and installed front calipers/rear drums before ordering.

    Source: BMWPartsDeal — exact-year 1978 BMW 320i brake-pad and shoe catalog listing · Genuine 1978 BMW 320i Brake Pads — Front Brake Pad Set 34111159249 and rear Brake Shoe Lining Repair Kit 34211160165 · checked

    Verified ordering references

    • Original equipmentBMW 34111159249

      Qty. 1 · Front axle · Asbestos-free front brake-pad set; replaces 34 11 1 150 527, 34 11 1 150 523, 34 11 1 118 517, and 34 11 1 150 524 · current

      One cataloged front-axle set; confirm the installed calipers and inspect rotors and hardware before ordering.

      Catalog: BMWPartsDeal — exact-year 1978 BMW 320i brake-pad and shoe catalog listing · Genuine 1978 BMW 320i Brake Pads — Front Brake Pad Set 34111159249 and supersession list · checked

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    • Original equipmentBMW 34211160165

      Qty. 1 · Rear axle · Asbestos-free rear brake-shoe lining repair kit; replaces 34 21 1 121 586, 34 21 1 108 430, and 34 21 1 111 484 · current

      One cataloged rear-axle shoe kit; confirm the installed drums and inspect cylinders and hardware before ordering.

      Catalog: BMWPartsDeal — exact-year 1978 BMW 320i brake-pad and shoe catalog listing · Genuine 1978 BMW 320i Brake Pads — rear Brake Shoe Lining Repair Kit 34211160165 and supersession list · checked

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  • Engine oil filter — catalog fitment

    Exact reference available

    Applies to: 1978 · United States

    2.0L fuel-injected M10 inline-four (110 hp / 112 lb-ft) — K&N HP-1002

    K&N HP-1002

    Manufacturer-catalog replacement-part fitment only; it does not establish a BMW service interval. Confirm the VIN, production date, engine, and installed filter dimensions before ordering.

    Applies to: 1978 · 2.0L fuel-injected M10 inline-four (110 hp / 112 lb-ft) · 320i · United States · Exact model-year and engine-family catalog scope; verify VIN and production date before ordering.

    Source: K&N — BMW 320i replacement oil-filter catalog · 1978 BMW 320i 1.8L/2.0L gasoline — HP-1002 · checked

    Verified ordering references

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Sources

  1. BMW of North America — first 3 Series U.S. history and specifications
  2. BMW of North America — new BMW 3 Series Sedan and Sports Wagon technical release
  3. Wikipedia — "BMW 3 Series"

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