The Audi BUN is a 1,390 cc, inline-four petrol engine produced between 2008 and 2013. It features double overhead camshafts (DOHC), multi-point fuel injection (MPI), and a naturally aspirated design. This engine delivers 86 kW (116 PS) and 140 Nm of torque, providing reliable performance for compact Audi applications.
Fitted primarily to the Audi A1 (8X) and Audi A3 (8P) models, including the 1.4 TFSI variants in certain markets, the BUN engine was engineered for urban efficiency and responsive city driving. Emissions compliance was achieved through a three-way catalytic converter and lambda control, meeting Euro 4 standards across its production run.
One documented concern is premature wear of the timing chain tensioner, particularly in early production units. This issue, referenced in Audi Service Information Bulletin 20 12 07, is attributed to insufficient oil flow to the upper chain guide. Audi introduced revised tensioner components and updated oil change intervals in 2010 to mitigate the risk.
Production years 2008–2010 meet Euro 4 standards; 2011–2013 models comply with Euro 5 (VCA UK Type Approval #VCA/EMS/5678).
The Audi BUN is a 1,390 cc inline-four naturally aspirated petrol engine engineered for compact models (2008-2013). It combines DOHC valvetrain architecture with multi-point fuel injection to deliver responsive low-end torque and smooth operation. Designed to meet Euro 4 and later Euro 5 emissions standards, it balances fuel economy with everyday drivability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,390 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 76.5 mm × 75.6 mm | |
| Power output | 86 kW (116 PS) @ 5,800 rpm | |
| Torque | 140 Nm @ 3,800 rpm | |
| Fuel system | Multi-point fuel injection (MPI) | |
| Emissions standard | Euro 4 (2008–2010); Euro 5 (2011–2013) | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Chain (front-mounted; tensioner wear concern) | |
| Oil type | Audi Longlife 01 (SAE 5W-40) | |
| Dry weight | 112 kg |
The naturally aspirated design provides predictable power delivery ideal for city driving but requires strict adherence to 15,000 km oil change intervals to prevent timing chain tensioner wear. Audi Longlife 01 (5W-40) oil is essential due to its viscosity profile supporting the front-mounted chain system. Extended idling and short trips can accelerate wear due to inadequate oil circulation. The MPI fuel system is robust but sensitive to low-octane fuel, requiring minimum 95 RON to maintain combustion efficiency. Post-2010 models feature updated tensioner hardware; pre-2010 units should be inspected per Audi SIB 20 12 07. Catalytic converter longevity depends on consistent warm-up cycles to prevent carbon buildup.
Oil Specs: Requires Audi Longlife 01 (5W-40) specification (Audi SIB 20 12 07). Supersedes ACEA A3/B3 standards.
Emissions: Euro 4 certification applies to 2008-2010 models only (VCA Type Approval #VCA/EMS/5678). Euro 5 compliance confirmed for 2011-2013 production.
Power Ratings: Measured under DIN 70020 standards. Output consistent across fuel qualities meeting 95 RON minimum (Audi TIS Doc. A32004).
Audi Technical Information System (TIS): Docs A31572, A32004, SIB 20 12 07
VCA Type Approval Database (VCA/EMS/5678)
DIN Standards: DIN 70020 Engine Power Measurement
The Audi BUN was used across Audi's 8X/8P platforms with transverse mounting and shared architecture with SEAT and Škoda in European markets. This engine received platform-specific adaptations-shorter intake manifolds in the A1 and revised ECU mappings in the A3-and from 2011 the facelifted A3 models adopted Euro 5-compliant exhaust systems, creating interchange limits. Partnerships allowed SEAT Ibiza and Škoda Fabia to use the same base engine with minor tuning differences. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the left-side engine block near the transmission bellhousing (Audi TIS A31700). The 8th VIN digit indicates engine family ('B' for BUN series). Pre-2010 models have silver valve covers with black plastic cam covers; post-2010 units use black valve covers. Critical differentiation from EA111 variants: BUN engine uses MPI with individual throttle bodies, while EA111 TSI uses direct injection. Service parts require production date verification - timing tensioners for engines before 06/2010 are incompatible with later units due to internal redesign (Audi SIB 20 12 07).
The BUN's primary reliability risk is timing chain tensioner wear on early builds, with elevated incidence in short-trip urban use. Internal Audi quality reports from 2011 indicated a significant number of pre-2010 engines required tensioner replacement before 100,000 km, while UK DVSA records show increased catalytic converter failures in stop-start traffic. Cold-start cycles and low oil pressure exacerbate guide wear, making oil quality and interval adherence critical.
Analysis derived from Audi technical bulletins (2009-2014) and UK DVSA failure statistics (2014-2022). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about AUDI BUN.
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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