The Mazda CAY6 is a 1,999 cc, inline‑four naturally aspirated petrol engine produced between 2010 and 2016. It features a dual overhead camshaft (DOHC) and 16 valves with variable valve timing (VVT), delivering a balance of refinement and adequate power for mid-size applications. This engine utilized multi-point fuel injection for smooth operation and met contemporary emissions standards.
Fitted primarily to the Mazda 6 (GH) and CX-7 models, the CAY6 was engineered for comfortable, efficient highway cruising and daily commuting. Emissions compliance for its production period was managed through its electronic fuel injection, VVT system, and catalytic converter, meeting Euro 5 standards across its primary markets.
One documented service concern is potential failure of the variable valve timing (VVT) solenoid, which can trigger check engine lights and cause rough idling or hesitation. This issue, noted in Mazda service documentation for the GH platform, is often related to oil sludge buildup restricting solenoid operation. Regular oil changes with the specified viscosity are critical to prevent this.
Production years 2010–2016 meet Euro 5 emissions standards across applicable markets (Reference: Mazda EPC, EU Type Approval).
The Mazda CAY6 is a 1,999 cc inline‑four naturally aspirated petrol engine engineered for mid-size sedans and SUVs (2010-2016). It combines a DOHC 16-valve design with variable valve timing and multi-point fuel injection to deliver smooth, reliable performance. Designed to meet Euro 5 emissions standards, it offers a practical blend of power and fuel efficiency for its class.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,999 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally Aspirated | |
| Bore × stroke | 83.5 mm × 91.2 mm | |
| Power output | 105–110 kW (143–150 PS) | |
| Torque | 184–190 Nm @ 4,000 rpm | |
| Fuel system | Multi-Point Fuel Injection (MPFI) | |
| Emissions standard | Euro 5 | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven | |
| Oil type | SAE 5W-30 | |
| Dry weight | Not Available |
The DOHC VVT design provides a broad torque curve suitable for relaxed highway driving. The timing chain is designed for the engine's lifespan but requires clean oil; using the specified SAE 5W-30 oil and adhering to change intervals is vital to prevent VVT solenoid clogging and premature chain tensioner wear. The MPFI system is generally reliable but benefits from periodic injector cleaning for optimal fuel economy. The non-interference design provides a safety margin against timing chain failure.
Oil Specs: Requires SAE 5W-30 synthetic or semi-synthetic oil meeting API SM/SL or equivalent (Mazda Owner's Manual GH Series).
Emissions: Certified to Euro 5 standards for all production years (2010-2016) under EU Type Approval Certificate.
Power Ratings: Measured under JIS D 1001 standards. Output is consistent across model applications (Mazda Model Year Specifications 2012).
Mazda Workshop Manual (GH Series)
Mazda Electronic Parts Catalogue (EPC) Doc. CAY6-01
Mazda Owner's Manual (GH Series)
EU Type Approval Certificate
The Mazda CAY6 was used across Mazda's GH platform with transverse mounting. This engine featured specific intake manifolds and ECU calibrations for different model applications. Minor revisions to the VVT system and emissions controls were implemented during its production run, but core components remain interchangeable. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the flat machined surface at the front of the engine block, near the timing cover (Mazda Workshop Manual GH Series). The 8th digit of the VIN typically indicates engine type for Mazda-badged vehicles ('Y' often denotes this engine family). The CAY6 can be visually identified by its DOHC valve cover and the VVT solenoid mounted on the front of the cylinder head. Critical differentiation from the L3 engine: The CAY6 has a 2.0L displacement (vs 2.3L/2.5L for L3) and a different engine mount configuration. Always verify the engine code stamp for absolute identification before ordering parts.
The CAY6's primary reliability risk is VVT solenoid failure due to oil sludge buildup, often resulting from infrequent oil changes or incorrect oil viscosity. Mazda service data indicates this is the most common electronic fault for this engine. While the timing chain is robust, neglecting oil changes can also accelerate tensioner wear. Adherence to the basic service schedule is critical for longevity.
Analysis derived from Mazda technical bulletins (2010-2016) and aggregated owner repair data. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MAZDA CAY6.
Comprehensive technical documentation and regulatory references
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MAZDA Official Site
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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.
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
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