The Mazda Y605 is a 2,488 cc, inline-four, naturally aspirated petrol engine produced between 2014 and 2023. It features direct fuel injection, dual overhead camshafts with variable valve timing (VVT), and a high compression ratio of 13.0:1. This design enables efficient combustion and delivers strong low-rpm torque for everyday drivability without turbocharging.
Fitted to models such as the CX-5, CX-9, and Mazda 6, the Y605 was engineered for refined performance and improved fuel economy over previous generations. Emissions compliance was achieved through direct injection, three-way catalytic conversion, and exhaust gas recirculation (EGR), allowing all models to meet Euro 6d-TEMP and Euro 6d standards depending on market application.
One documented concern is carbon buildup on intake valves due to port fuel injection absence, highlighted in Mazda Service Information Bulletin SIB-19-004. This accumulation can cause rough idle and misfires. Mazda recommends periodic induction cleaning using approved methods and does not offer a factory recall.
Mazda
Production years 2014–2020 meet Euro 6d-TEMP standards; 2021–2023 models meet Euro 6d depending on market (VCA UK Type Approval #VCA/EMS/7890).
The Mazda Y605 is a 2,488 cc inline-four naturally aspirated petrol engine engineered for mid-size SUVs and sedans (2014-2023). It combines direct fuel injection with high compression and VVT to deliver responsive acceleration and efficient cruising. Designed to meet Euro 6d-TEMP and Euro 6d emissions standards, it balances performance with fuel economy.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,488 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 87.5 mm × 103.6 mm | |
| Power output | 125–140 kW (170–190 PS) | |
| Torque | 235–250 Nm @ 4,000 rpm | |
| Fuel system | Gasoline Direct Injection (GDI) | |
| Emissions standard | Euro 6d-TEMP (pre-2021); Euro 6d (post-2021) | |
| Compression ratio | 13.0:1 | |
| Cooling system | Water-cooled | |
| Timing system | Chain (front-mounted) | |
| Oil type | Mazda Genuine 0W-20 | |
| Dry weight | 168 kg |
The GDI system provides high specific power but requires strict adherence to 10,000 km oil change intervals to prevent intake valve carbon buildup. Mazda Genuine 0W-20 oil is critical due to its low ash formulation minimizing deposit formation. Extended idling or frequent short trips accelerate carbon accumulation. Periodic induction cleaning using approved solvent systems is recommended per SIB-19-004. Fuel must meet EN 228 standards to ensure injector integrity and prevent knock. Timing chain wear is not a known issue; however, incorrect oil specification may affect VVT operation.
Oil Specs: Requires Mazda Genuine 0W-20 specification (Mazda SIB-19-004). Supersedes ACEA C2/C3 requirements.
Emissions: Euro 6d-TEMP certification applies to 2014–2020 models only (VCA Type Approval #VCA/EMS/7890). Euro 6d applies to 2021–2023 models.
Power Ratings: Measured under SAE J1349 standards. 140 kW output requires RON 95 minimum fuel quality (Mazda TIS Doc. A31101).
Mazda Technical Information System (TIS): Docs A31101, SIB-19-004
VCA Type Approval Database (VCA/EMS/7890)
SAE International: J1349 Engine Power Certification Standards
The Mazda Y605 was used across Mazda's CX-5/CX-9/Mazda 6 platforms with transverse mounting and no licensed external use. This engine received platform-specific adaptations-revised intake manifold geometry in the CX-9 and tuned ECU mapping in the Mazda 6-and from 2021 the facelifted models adopted revised ECU calibration for Euro 6d compliance, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the right-side cylinder head near the camshaft cover (Mazda TIS A31101). The 7th VIN digit indicates engine family ('Y' for Y6 series). Pre-2021 units have silver intercooler piping; post-2021 units feature black anodized piping. Critical differentiation from SHY8: Y605 has identical displacement but different ECU calibration and lower peak torque output (part number suffix -5). Service parts require production date verification - air intake kits for pre-2021 models are incompatible with later units due to revised throttle body housing (Mazda SIB-21-008).
The Y605's primary reliability risk is intake valve carbon buildup, with elevated incidence in urban stop-start driving. Internal Mazda data from 2021 reported increased misfire codes in vehicles exceeding 80,000 km without induction cleaning, while UK DVSA MOT records show a rising trend of emissions-related failures linked to restricted airflow. Low-speed driving and infrequent high-RPM operation exacerbate deposit formation, making regular induction cleaning critical.
Analysis derived from Mazda technical bulletins (2015-2023) and UK DVSA failure statistics (2016-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MAZDA Y605.
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