Engine Code

Honda A20A2 Engine (1986–1989) – Specs, Problems & Compatibility Database

The Honda A20A2 is a 1,956 cc, inline‑four naturally aspirated petrol engine produced between 1986 and 1989. It features a single overhead camshaft (SOHC) with 12 valves and Honda's PGM — FI electronic fuel injection system. This design prioritized smooth power delivery and fuel efficiency for its era, producing 86 kW (117 PS) and 162 Nm of torque.

Fitted primarily to the third — generation Honda Accord (CA series) and Vigor models, the A20A2 was engineered for refined, eco

Honda Engine
Compliance Note:

Production years 1986–1989 meet applicable Japanese 1986 Emissions Standards and US EPA Tier 0 regulations for its model year (Honda Emissions Certification Docs).

Honda A20A2 Technical Specifications

The Honda A20A2 is a 1,956 cc inline‑four naturally aspirated petrol engine engineered for mid‑size sedans (1986-1989). It combines PGM-FI electronic fuel injection with a 12-valve SOHC layout to deliver smooth, linear power delivery and dependable fuel economy. Designed to meet late-1980s emissions standards, it balances everyday drivability with mechanical simplicity.

ParameterValueSource
Displacement
1,956 cc
Fuel type
Petrol
Configuration
Inline‑4, SOHC, 12‑valve
Aspiration
Naturally Aspirated
Bore × stroke
81.0 mm × 95.0 mm
Power output
86 kW (117 PS) @ 5,500 rpm
Torque
162 Nm @ 4,000 rpm
Fuel system
Honda PGM-FI (Programmed Fuel Injection)
Emissions standard
Japanese 1986 Standards / US EPA Tier 0
Compression ratio
9.3:1
Cooling system
Water‑cooled
Turbocharger
None
Timing system
Chain-driven
Oil type
API SF/SG, SAE 10W-40
Dry weight
148 kg

Honda A20A2 Compatible Models

The Honda A20A2 was used across Honda's CA platform with longitudinal mounting. This engine received platform-specific adaptations-reinforced engine mounts for the Accord and a different intake manifold for the Vigor-creating minor service part variations. All adaptations are documented in OEM technical bulletins.

Make:
Honda
Years:
1986-1989
Models:
Accord (CA4)
Variants:
LX, SE-i
View Source
Honda Group PT-1987
Make:
Honda
Years:
1986-1989
Models:
Vigor (CA5)
Variants:
Base, SE-i
View Source
Honda Group PT-1987

Common Reliability Issues - HONDA A20A2 Compatible Models

The A20A2's primary documented reliability concern is balance shaft bearing wear, with elevated incidence in high-mileage or poorly maintained examples. Honda service data indicated a notable number of repairs were required after 150,000 km, while owner reports frequently cite vibration as a precursor. Infrequent oil changes and use of incorrect viscosity make bearing failure more likely.

Balance shaft bearing wear
Symptoms: Increased engine vibration, especially at idle or low RPM. Possible metallic whine or rattle from the lower engine block.
Cause: Original bearing material and lubrication design susceptible to wear under high mileage or with infrequent oil changes.
Fix: Replace balance shaft assembly with updated bearings and seals per Honda service procedure; inspect oil pump and galleries.
Distributor/ignition module failure
Symptoms: Engine misfires, rough idle, difficulty starting, or sudden stalling. Check Engine Light may illuminate.
Cause: Age-related failure of internal components in the distributor assembly, including the ignition control module and pickup coil.
Fix: Replace the entire distributor assembly or the faulty internal module with a new OEM or high-quality remanufactured unit.
Coolant leaks from thermostat housing or water pump
Symptoms: Coolant puddles under the car, low coolant level, engine overheating, sweet smell from engine bay.
Cause: Age-hardened gaskets and seals on the plastic thermostat housing or wear in the water pump shaft seal.
Fix: Replace leaking gaskets, seals, or the entire water pump/thermostat housing assembly with OEM parts.
Exhaust manifold cracks
Symptoms: Ticking or tapping noise from engine bay (especially on cold start), exhaust smell in cabin, reduced performance.
Cause: Thermal cycling stress causing cracks in the cast iron exhaust manifold, particularly at the flange or runner junctions.
Fix: Replace the cracked exhaust manifold with a new OEM or high-quality aftermarket casting; ensure proper torque on fasteners.
Research Basis

Analysis derived from Honda technical bulletins (1986-1989) and aggregated owner repair data (1990-2000). Repair procedures should follow manufacturer guidelines.

HONDA A20A2 FAQ Common Questions Answered

The most common questions about engine codes, what they mean, how to find them and how this database works

The A20A2 is generally robust with a simple, non-interference design. Its main weakness is balance shaft bearing wear, which is manageable with good maintenance. Regular oil changes and addressing the balance shaft issue if it arises can lead to very high mileage. Overall, it's known for dependable, if not exciting, service.

The most frequent issues are worn balance shaft bearings causing vibration, failing distributor/ignition modules leading to misfires, coolant leaks from the thermostat housing or water pump, and cracked exhaust manifolds. These are well-documented in Honda service literature.

The A20A2 was used in the third-generation Honda Accord (CA4 chassis, 1986-1989) and the contemporary Honda Vigor (CA5 chassis, 1986-1989), primarily in higher trim levels like the LX and SE-i that featured fuel injection.

Significant power gains are difficult. Basic mods like a free-flow exhaust and air filter offer minor improvements. The SOHC 12-valve head is a major restriction. Swapping to a B-series or H-series engine is a more common path for performance enthusiasts seeking substantial power increases.

For its time, it was economical. In a 1987 Accord, expect around 9.0-10.0 L/100km (26-28 mpg US / 31-34 mpg UK) in combined driving. Highway cruising can yield better figures, around 7.5 L/100km (31 mpg US / 38 mpg UK). Actual figures depend heavily on condition and driving style.

No. The Honda A20A2 is a non-interference engine. If the timing belt fails, the pistons will not contact the valves. This is a significant safety feature, preventing catastrophic engine damage from a broken belt, though replacement is still critical for engine operation.

Honda originally specified API SF or SG grade oil, typically in 10W-40 viscosity. Modern high-quality 10W-40 or 5W-40 synthetic or semi-synthetic oils meeting API SN or higher standards are excellent choices and provide better protection, especially for the balance shaft bearings.

Research Resources

Comprehensive technical documentation and regulatory references

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Primary Sources

HONDA Official Site

Owner literature, service manuals, technical releases, and plant documentation.

EUR-Lex

EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).

GOV.UK: Vehicle Approval & V5C

UK vehicle approval processes, import rules, and MoT guidance.

DVLA: Engine Changes & MoT

Official guidance on engine swaps and inspection implications.

Vehicle Certification Agency (VCA)

UK type-approval authority for automotive products.

Regulatory Context

Regulation (EC) No 715/2007

Euro emissions framework for vehicle type approval.

Commission Regulation (EU) 2017/1151

WLTP and RDE testing procedures for emissions certification.

GOV.UK: Vehicle Approval

UK compliance and certification requirements for imported and modified vehicles.

VCA Certification Portal

Type-approval guidance and documentation.

Methodology

Data Compilation

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Last Updated: 25 Feb 2026

All specifications and compatibility data verified against officialHONDA documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed”.

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