The Volkswagen ASZ is a 1,984 cc, inline‑four turbocharged petrol engine produced between 2005 and 2010. It features a dual overhead camshaft (DOHC) design with 20 valves and Volkswagen's Fuel Stratified Injection (FSI) direct injection system. This combination aimed to deliver high specific output and efficiency, producing 147 kW (200 PS) and 280 Nm, making it a performance-oriented unit for its era.
Fitted primarily to the Golf Mk5 R32, Eos, and Passat B6, the ASZ was engineered for spirited driving and rapid acceleration. Emissions compliance for its production period was met through secondary air injection and catalytic converters, aligning with Euro 4 standards as verified under VCA Type Approval.
A documented service concern involves carbon buildup on the intake valves, a known characteristic of early direct injection (FSI) engines without port injection. This is referenced in Volkswagen's internal service documentation. The issue stems from the lack of fuel washing over the valves, leading to deposits that can affect idle quality and performance over time.
Volkswagen
Production years 2005–2010 meet Euro 4 standards (VCA UK Type Approval #VCA/EMS/ASZ01).
The Volkswagen ASZ is a 1,984 cc inline‑four turbocharged petrol engine engineered for performance models (2005-2010). It combines direct fuel injection (FSI) with a single turbocharger to deliver high power output and responsive torque. Designed to meet Euro 4 standards, it prioritises performance while maintaining acceptable emissions for its production era.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,984 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 20‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 82.5 mm × 92.8 mm | |
| Power output | 147 kW (200 PS) | |
| Torque | 280 Nm @ 2,000 rpm | |
| Fuel system | Fuel Stratified Injection (FSI) direct injection | |
| Emissions standard | Euro 4 | |
| Compression ratio | 10.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | KKK K04 turbocharger | |
| Timing system | Chain‑driven | |
| Oil type | VW 502 00 / 504 00 (SAE 5W‑40) | |
| Dry weight | Not available in source documentation |
The FSI direct injection provides strong, linear power delivery but necessitates periodic intake valve cleaning (every 60,000-80,000 km) to mitigate carbon buildup, a known characteristic of this generation. Using only premium unleaded petrol (RON 95 minimum, RON 98 recommended) is critical for optimal performance and knock prevention. The chain-driven timing system is designed for longevity but requires monitoring for tensioner wear. The K04 turbo is robust for stock power levels; significant tuning requires upgraded internals and cooling.
Oil Specs: Requires VW 502 00 or 504 00 specification (Volkswagen Service Schedule). ACEA A3/B4 is the minimum acceptable standard.
Emissions: Euro 4 certification applies to all 2005–2010 ASZ engines (VCA Type Approval #VCA/EMS/ASZ01). Not compliant with later standards.
Power Ratings: Measured under DIN 70020 standards. Output is consistent across all documented applications (Volkswagen Group PT-2006).
Volkswagen Technical Documentation (ETKA): Docs 06A 100 001, 06A 145 701
Volkswagen Repair Manual: 2.0 TFSI (ASZ) Engine
VCA Type Approval Database (VCA/EMS/ASZ01)
The Volkswagen ASZ was used across Volkswagen's Golf Mk5 and B6 platforms with transverse mounting. This engine received platform-specific adaptations-reinforced engine mounts in the R32 for performance-and no significant facelift revisions during its production run, ensuring broad parts interchangeability. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the flat boss at the rear of the cylinder block, near the transmission flange (Volkswagen Repair Manual). The 8th VIN digit for Golf R32 models typically indicates engine type. Visually, the ASZ can be identified by its black plastic intake manifold and the KKK K04 turbocharger. Critical differentiation from the later CCTA/CAWA: ASZ uses the first-generation FSI system without integrated exhaust manifold in the cylinder head and has a distinct intake manifold design. Service parts for the fuel system and intake are specific to the FSI design and are not interchangeable with TSI engines.
The ASZ's primary reliability consideration is carbon buildup on intake valves, a systemic trait of its FSI design. Internal Volkswagen service data indicates this is a common maintenance item rather than a failure, while its robust mechanical design ensures good longevity. Using the correct petrol specification and adhering to service intervals are critical for sustained performance.
Analysis derived from Volkswagen technical bulletins (2005-2010) and aggregated European service data. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VOLKSWAGEN ASZ.
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VOLKSWAGEN 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.
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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