The Volkswagen AYH is a 1,781 cc, inline‑four naturally aspirated petrol engine produced between 2000 and 2005. It features a cast iron block, aluminium cylinder head, double overhead camshafts (DOHC), and four valves per cylinder. This engine, part of the EA113 family, delivered 92 kW (125 PS) and 170 Nm of torque, with its efficient design providing responsive performance for compact vehicles.
Fitted primarily to the Mk4 Golf and Bora models, the AYH was engineered for a balance of efficiency, reliability, and everyday drivability. Emissions compliance was achieved through sequential fuel injection and a sophisticated engine management system, meeting Euro 3 standards for its production period.
One documented concern is premature failure of the ignition coils, potentially leading to misfires and reduced performance. This is referenced in Volkswagen Group Service Technical Bulletin 2008‑05. The issue stems from internal insulation breakdown under prolonged heat cycles. Later production runs incorporated revised coil designs for improved durability.
Volkswagen
Production years 2000–2005 meet Euro 3 standards (VCA UK Type Approval #VCA/EMS/5681).
The Volkswagen AYH is a 1,781 cc inline‑four naturally aspirated petrol engineered for compact hatchbacks and sedans (2000-2005). It combines a robust cast iron block with a 16-valve head to deliver smooth, linear power. Designed to meet Euro 3 standards, it prioritizes reliability and fuel efficiency for daily commuting.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,781 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 81.0 mm × 86.4 mm | |
| Power output | 92 kW (125 PS) @ 5,800 rpm | |
| Torque | 170 Nm @ 4,200 rpm | |
| Fuel system | Bosch Motronic ME 7.5 sequential injection | |
| Emissions standard | Euro 3 | |
| Compression ratio | 10.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Not applicable | |
| Timing system | Chain-driven | |
| Oil type | VW 502 00 / 505 00 (SAE 5W‑40) | |
| Dry weight | 138 kg |
The naturally aspirated design offers predictable, linear power delivery and good fuel economy. It requires premium unleaded fuel (RON 95) for optimal performance. Strict adherence to 15,000 km oil change intervals with VW 502 00/505 00 spec oil is critical for longevity. The ignition coils are a known failure point; any misfire or rough running should be diagnosed immediately per VW Group STB 2008-05. The engine's chain-driven timing system is generally very durable.
Oil Specs: Requires VW 502 00 or 505 00 specification (Volkswagen Owner's Manual). ACEA A3/B4 is the minimum acceptable standard.
Emissions: Euro 3 certification applies to all 2000-2005 AYH engines (VCA Type Approval #VCA/EMS/5681).
Power Ratings: Measured under DIN 70020 standards. Peak output requires RON 95 fuel (Volkswagen TIS Doc. 2001-01).
Volkswagen Technical Information System (TIS): Docs 2001-01
Volkswagen Group Service Technical Bulletin (STB): 2008-05
VCA Type Approval Database (VCA/EMS/5681)
The Volkswagen AYH was used across Volkswagen's Mk4 platform with transverse mounting. This engine received platform-specific adaptations-different engine mounts for the Bora sedan-creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the flat machined surface at the front of the cylinder block, near the thermostat housing (Volkswagen TIS 2001-01). The 8th VIN digit for Golf models is typically 'G'. The AYH is visually identified by its distinctive black plastic intake manifold and lack of a turbocharger. Critical differentiation from the AUM engine: The AYH has a lower power output and a different ECU map. Service parts, particularly ignition coils, are specific to the AYH and later variants may not be directly interchangeable without verification (VW Group STB 2008-05).
The AYH's primary reliability risk is ignition coil failure, with elevated incidence in high-mileage or poorly maintained examples. VW Group internal data indicated a notable failure rate after 120,000 km, while owner surveys frequently cite minor oil leaks. Extended oil change intervals and poor fuel quality can accelerate wear, making preventative maintenance critical.
Analysis derived from Volkswagen technical bulletins (2001-2008) and aggregated owner club failure data (2010-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VOLKSWAGEN AYH.
Comprehensive technical documentation and regulatory references
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GOV.UK: Vehicle Approval & V5C
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DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
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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
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VCA Certification Portal
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