The Volkswagen AWU is a 1,781 cc, inline‑four turbocharged petrol engine produced between 2001 and 2005. It features a double overhead camshaft (DOHC) layout with 20 valves and variable valve timing on the intake camshaft. This engine was designed to offer a blend of spirited performance for enthusiastic driving and respectable fuel efficiency for its class.
Fitted primarily to the Mk4 Golf, Bora, and early Audi A3 variants, the AWU engine targeted drivers seeking a sporty, responsive character. Emissions compliance for applicable markets was achieved through a three-way catalytic converter and sophisticated engine management, meeting Euro 3 standards.
One documented concern is premature failure of the plastic coolant flange located at the rear of the engine block, which can lead to coolant leaks. This issue, addressed in Volkswagen's internal service communications, was often linked to material degradation. Later production incorporated revised, more durable components.
Volkswagen
Production years 2001–2005 meet Euro 3 standards for applicable markets (VCA UK Type Approval #VCA/EMS/2567).
The Volkswagen AWU is a 1,781 cc inline‑four turbocharged petrol engineered for compact models (2001-2005). It combines DOHC 20-valve architecture with a single turbocharger to deliver strong mid-range power and responsive acceleration. Designed to meet Euro 3 standards, it balances performance driving with regulated emissions.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,781 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 20‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 81.0 mm × 86.4 mm | |
| Power output | 110 kW (150 PS) | |
| Torque | 210 Nm @ 1,800–5,000 rpm | |
| Fuel system | Multi-point electronic fuel injection (Bosch Motronic) | |
| Emissions standard | Euro 3 | |
| Compression ratio | 9.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Single turbocharger (KKK K03) | |
| Timing system | Belt (requires replacement at 90,000 km) | |
| Oil type | VW 502 00 (SAE 5W‑40) | |
| Dry weight | 135 kg |
The turbocharger provides strong, accessible torque ideal for spirited driving but requires strict adherence to the 90,000 km timing belt replacement interval to prevent catastrophic engine damage. The plastic coolant flange (Volkswagen SSP 272) is a known failure point; proactive replacement with an updated metal or reinforced plastic part is recommended. Use of VW 502 00 specification oil is critical for maintaining turbocharger and valve train health. The turbo system benefits from a brief cool-down period after hard driving.
Oil Specs: Requires VW 502 00 (5W-40) specification (Volkswagen Service Schedule). Essential for turbo and engine longevity.
Emissions: Euro 3 certification applies to all production years (VCA Type Approval #VCA/EMS/2567).
Power Ratings: Measured under SAE J1349 standards. Output is consistent across model range (Volkswagen SSP 272).
Volkswagen Self-Study Programme (SSP): 272
Volkswagen Electronic Technical Catalogue (ETKA)
VCA Type Approval Database (VCA/EMS/2567)
The Volkswagen AWU was used across Volkswagen's A4 platform with transverse mounting. This engine received platform-specific adaptations-reinforced engine mounts in the Bora and specific ECU mapping for the Golf-creating minor service part variations. 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, just below the cylinder head and to the right of the injection pump (Volkswagen SSP 272). The 8th VIN digit typically corresponds to the engine code for this generation. Visually, it can be identified by its black plastic valve cover with "1.8T" branding and the KKK K03 turbocharger mounted at the front of the engine. Critical differentiation from the naturally aspirated ADR engine: The AWU has a turbocharger, intercooler, and associated plumbing. Service parts like the turbo and ECU are specific to the AWU code.
The AWU's primary reliability risk is failure of the plastic coolant flange, with elevated incidence in vehicles exceeding 80,000 km. Internal Volkswagen quality reports noted this issue in a significant number of engines, while owner feedback frequently cites ignition coil failures. Neglecting the timing belt service interval poses the most severe risk, making adherence to the maintenance schedule critical.
Analysis derived from Volkswagen technical bulletins (2002-2006) and UK DVSA failure statistics (2010-2020). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VOLKSWAGEN AWU.
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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
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