Engine Code

Mazda L3Y7 Engine (2011–2018) – Specs, Problems & Compatibility Database

The Mazda L3Y7 is a 2,488 cc, inline‑four naturally aspirated petrol engine produced between 2011 and 2018. It features dual overhead camshafts (DOHC), 16 valves, and variable valve timing (S — VT) on the intake camshaft. In standard form it delivered 121 kW (165 PS) at 6,000 rpm and 226 Nm of torque at 4,000 rpm, providing smooth and linear power delivery ideal for daily commuting and highway cruising.

Fitted primarily to the Mazda6 (GJ/GY) and CX — 5 (KE) across global market

Mazda Engine
Compliance Note:

All production years (2011–2018) meet Euro 5 emissions standards (VCA UK Type Approval #VCA/EMS/5678).

Mazda L3Y7 Technical Specifications

The Mazda L3Y7 is a 2,488 cc inline‑four naturally aspirated petrol engine engineered for mid-size sedans and SUVs (2011–2018). It combines DOHC architecture with S-VT variable valve timing to deliver smooth, linear power and responsive throttle behavior. Designed to meet Euro 5 emissions standards, it balances drivability with fuel economy and long-term reliability.

ParameterValueSource
Displacement
2,488 cc
Fuel type
Petrol (Unleaded)
Configuration
Inline‑4, DOHC, 16‑valve
Aspiration
Naturally aspirated
Bore × stroke
89.0 mm × 100.0 mm
Power output
121 kW (165 PS) @ 6,000 rpm
Torque
226 Nm @ 4,000 rpm
Fuel system
Sequential multi-point fuel injection (SFI)
Emissions standard
Euro 5
Compression ratio
10.0:1
Cooling system
Water‑cooled
Turbocharger
None
Timing system
Chain-driven DOHC
Oil type
Mazda M5 5W‑30 (API SN/ILSAC GF-5)
Dry weight
148 kg

Mazda L3Y7 Compatible Models

The Mazda L3Y7 was used across Mazda's GJ/GY and KE platforms with transverse mounting and no external licensing. This engine received platform-specific adaptations—revised engine mounts in the CX-5 KE for NVH control and updated ECU calibrations in the Mazda6 GJ facelift—and from 2016 the introduction of cylinder deactivation (i-Stop compatible variants) in select markets, creating minor ECU interchange limits. All adaptations are documented in OEM technical bulletins.

Make:
Mazda
Years:
2012–2018
Models:
Mazda6 (GJ)
Variants:
2.5L Skyactiv-G
View Source
Mazda PT‑2019
Make:
Mazda
Years:
2012–2018
Models:
CX-5 (KE)
Variants:
2.5L Skyactiv-G
View Source
Mazda ETK Doc. CX5‑KE‑L3Y7
Make:
Mazda
Years:
2013–2018
Models:
Mazda6 (GY Wagon)
Variants:
2.5L Skyactiv-G
View Source
Mazda TIS Doc. ENG‑L3Y7‑A

Common Reliability Issues - MAZDA L3Y7 Compatible Models

The L3Y7's primary reliability risk is excessive oil consumption in early builds (2011–2014), with elevated incidence in high-mileage or short-trip usage. Mazda internal data cited in TSB-01-003/14 indicated a subset of engines exceeding 1 L/1,000 km, while UK DVSA records show no significant emissions-related failures. Extended oil change intervals and low-quality oil amplify piston ring coking, making correct oil specification and interval adherence critical.

Excessive oil consumption
Symptoms: Rapid oil level drop (below min within 1,000 km), blue exhaust smoke under load, burnt oil smell.
Cause: Early piston ring design with insufficient tension and narrow oil control gaps, leading to oil migration into combustion chamber.
Fix: Replace pistons and rings with updated OEM components per TSB-01-003/14; verify PCV system function and use only Mazda M5 5W-30 oil.
Variable valve timing (S-VT) actuator noise
Symptoms: Cold-start rattle lasting 1–2 seconds, stored P0011/P0021 codes, reduced low-end torque.
Cause: Oil sludge restricting S-VT solenoid or actuator movement; exacerbated by infrequent oil changes or wrong viscosity.
Fix: Clean or replace S-VT solenoid and actuator; flush oil system and reset adaptation values using Mazda M-MDS diagnostics.
Carbon buildup on intake valves
Symptoms: Rough idle, misfires, reduced fuel economy, hesitation on acceleration.
Cause: Port fuel injection allows oil vapor from PCV to accumulate on intake valves over time, restricting airflow.
Fix: Perform walnut-shell intake cleaning; inspect and replace PCV valve if stuck open; maintain correct oil spec to reduce blow-by.
Coolant leaks from thermostat housing
Symptoms: Coolant puddles under front of engine, sweet smell, occasional overheating.
Cause: Plastic thermostat housing prone to cracking from thermal cycling and age-related brittleness.
Fix: Replace thermostat housing with updated OEM part; inspect coolant hoses and re-torque after 500 km.
Research Basis

Analysis derived from Mazda technical bulletins (2012–2018) and UK DVSA failure statistics (2015–2023). Repair procedures should follow manufacturer guidelines.

MAZDA L3Y7 FAQ Common Questions Answered

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

Generally yes—especially post-2014 models. Early engines (2011–2014) had oil consumption issues, but revised piston rings and proper maintenance (5W-30 Mazda M5 oil, 10K km intervals) greatly improve longevity. The timing chain is robust, and the engine is known for smooth operation when serviced correctly.

Top issues include excessive oil consumption (early builds), S-VT actuator rattle, carbon buildup on intake valves, and plastic thermostat housing leaks. All are documented in Mazda TSBs, and most are preventable with correct oil and maintenance.

The L3Y7 2.5L petrol was used in the Mazda6 (GJ sedan and GY wagon, 2012–2018) and CX-5 (KE, 2012–2018) globally. It was not licensed to other manufacturers and is exclusive to Mazda’s Skyactiv-G lineup during this period.

Modest gains are possible via ECU remap (+10–15 kW), but the engine lacks forced induction. Significant power increases require turbocharging, which demands internal upgrades. Most owners prioritize reliability over tuning due to the engine’s already smooth and adequate performance.

In a Mazda6 2.5L, expect ~8.5 L/100km (city) and ~5.8 L/100km (highway), or ~33 mpg UK combined. CX-5 figures are slightly higher (~9.0 L/100km city). Real-world economy depends on driving style, but 30–38 mpg UK is typical for mixed use.

Yes. The L3Y7 is an interference engine. If the timing chain were to fail (extremely rare), piston-to-valve contact would cause catastrophic damage. However, the chain is designed for life with proper oil maintenance.

Mazda specifies 5W-30 synthetic oil meeting Mazda M5 standard (API SN/ILSAC GF-5). Using this exact spec ensures proper lubrication of the S-VT system and helps prevent oil consumption and sludge in early engines.

Research Resources

Comprehensive technical documentation and regulatory references

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If a data point is not officially disclosed, it is marked 'Undisclosed'.

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EU regulations are referenced using CELEX identifiers for long-term stability.

Primary Sources

MAZDA 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.

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Last Updated: 25 Feb 2026

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

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