The Volkswagen AUB is a 1,781 cc, inline‑four naturally aspirated petrol engine produced between 2000 and 2005. It features a dual overhead camshaft (DOHC) design with 20 valves and Volkswagen's variable valve timing system on the intake camshaft. This configuration aimed to balance efficiency with a broad, usable power band, delivering 92 kW (125 PS) and 170 Nm.
Fitted to models like the Golf Mk4, Bora, and New Beetle, the AUB was engineered for responsive everyday driving and refinement. Emissions compliance for its production period was met through a three-way catalytic converter and oxygen sensor feedback, aligning with Euro 3 standards as verified under VCA Type Approval.
A documented service consideration is wear of the variable valve timing (VVT) solenoid and associated oil control valve, which can lead to timing errors and reduced performance. This is referenced in Volkswagen's internal service documentation. The issue is often linked to sludge buildup from infrequent oil changes affecting solenoid operation.
Volkswagen
Production years 2000–2005 meet Euro 3 standards (VCA UK Type Approval #VCA/EMS/AUB01).
The Volkswagen AUB is a 1,781 cc inline‑four naturally aspirated petrol engineered for compact hatchbacks and sedans (2000-2005). It combines a 20-valve cylinder head with variable valve timing on the intake cam to deliver a broad, responsive power curve. Designed to meet Euro 3 standards, it prioritises smooth, linear power delivery for daily driving.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,781 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 20‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 81.0 mm × 86.4 mm | |
| Power output | 92 kW (125 PS) | |
| Torque | 170 Nm @ 4,200 rpm | |
| Fuel system | Bosch Motronic MPI (multi-point injection) | |
| Emissions standard | Euro 3 | |
| Compression ratio | 10.3:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Not applicable | |
| Timing system | Chain‑driven (primary), belt‑driven (secondary cams) | |
| Oil type | VW 502 00 (SAE 5W‑40) | |
| Dry weight | Not available in source documentation |
The 20-valve head provides a smooth, rev-happy character but requires strict 10,000-15,000 km oil changes with VW 502 00 specification to prevent sludge buildup that can clog the VVT solenoid. The secondary timing belt (driving exhaust cams) must be replaced at 80,000-100,000 km intervals alongside the primary chain inspection. Using premium unleaded petrol (RON 95) is recommended for optimal performance and to prevent knocking, though RON 91 is the minimum. The chain-driven primary timing is generally robust but should be inspected for tensioner wear during belt service.
Oil Specs: Requires VW 502 00 specification (Volkswagen Service Schedule). ACEA A3/B3 is the minimum acceptable standard.
Emissions: Euro 3 certification applies to all 2000–2005 AUB engines (VCA Type Approval #VCA/EMS/AUB01). Not compliant with later standards.
Power Ratings: Measured under DIN 70020 standards. Output is consistent across all applications (Volkswagen Group PT-2001).
Volkswagen Technical Documentation (ETKA): Docs 06A 100 001
Volkswagen Repair Manual: 1.8 20V (AUB) Engine
VCA Type Approval Database (VCA/EMS/AUB01)
The Volkswagen AUB was used across Volkswagen's Golf Mk4 and Bora platforms with transverse mounting. This engine received platform-specific adaptations-reinforced engine mounts in the New Beetle for NVH control-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 Mk4 models typically indicates engine type. Visually, the AUB can be identified by its silver plastic intake manifold and the '20V' badge on the engine cover. Critical differentiation from the turbocharged AUM/APX: AUB is naturally aspirated with no turbo or intercooler plumbing. The variable valve timing solenoid is mounted on the front of the cylinder head, driven by the primary timing chain.
The AUB's primary reliability consideration is failure of the variable valve timing (VVT) solenoid, with elevated incidence in vehicles subjected to infrequent oil changes. Internal Volkswagen service data indicates sludge buildup is a common root cause, while its robust mechanical design otherwise ensures good longevity. Adhering to the correct oil specification and change interval is critical to prevent this issue.
Analysis derived from Volkswagen technical bulletins (2000-2005) and aggregated European service data. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VOLKSWAGEN AUB.
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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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