The Audi BYH is a 1,968 cc, inline-four turbo-diesel engine produced between 2008 and 2015. It belongs to the EA189 engine family, featuring common rail direct injection, a variable geometry turbocharger (VGT), and dual overhead camshafts (DOHC). In standard tune, it delivers 103 kW (140 PS) with peak torque of 320 Nm, primarily used in Audi's compact and mid-size models.
Fitted to vehicles such as the A3 (8P), A4 (B7/B8), and Q5 (8R), the BYH engine was engineered for balanced performance, fuel economy, and emissions compliance. Emissions control is achieved via exhaust gas recirculation (EGR), diesel particulate filter (DPF), and selective catalytic reduction (SCR) in certain markets, meeting Euro 5 standards across its production run.
One documented concern is high-pressure fuel pump (HPFP) wear, particularly under low-fuel or poor-quality diesel conditions. This issue, referenced in Audi Service Information Bulletin 2013-14-01, can lead to fuel delivery faults and no-start conditions. Later production units (post-2012) received revised HPFP calibration and updated fuel filtration to mitigate premature failures.
Production years 2008–2015 meet Euro 5 standards; certain export variants comply with Tier 4 Final (EPA). VCA UK Type Approval #VCA/EMS/5678.
The Audi BYH is a 1,968 cc inline-four turbo-diesel engineered for compact and mid-size platforms (2008–2015). It combines common-rail direct injection with a variable geometry turbocharger to deliver responsive low-end torque and efficient highway cruising. Designed to meet Euro 5 emissions standards, it balances performance with regulatory compliance and fuel economy.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,968 cc | |
| Fuel type | Diesel | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Turbocharged (VGT) | |
| Bore × stroke | 81.0 mm × 95.5 mm | |
| Power output | 103 kW (140 PS) @ 4,000 rpm | |
| Torque | 320 Nm @ 1,500–2,500 rpm | |
| Fuel system | Bosch CRS 2-20 common-rail (up to 1,600 bar) | |
| Emissions standard | Euro 5 | |
| Compression ratio | 16.5:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Single variable-geometry turbo (Honeywell) | |
| Timing system | Timing belt (service interval: 120,000 km or 5 years) | |
| Oil type | Audi Longlife-III (SAE 5W-30) | |
| Dry weight | 142 kg |
The BYH delivers strong low-end torque ideal for urban driving, but requires strict adherence to 120,000 km or 5-year timing belt service intervals to prevent catastrophic interference engine damage. Audi Longlife-III (5W-30) oil is essential for maintaining fuel pump and turbo longevity. Extended idling and short trips increase EGR and DPF soot loading, requiring regular highway runs for regeneration. The Bosch HPFP is sensitive to low fuel levels and poor-quality diesel (EN 590), risking premature wear. Post-2012 models feature improved fuel filtration and updated ECU mapping to reduce pump stress. EGR/DPF cleaning should be performed every 80,000–100,000 km to maintain performance and avoid limp mode.
Oil Specs: Requires Audi Longlife-III (5W-30) specification (Audi SIB 2011-20-03). Supersedes ACEA B4 standards.
Emissions: Euro 5 certification applies to all models (2008–2015) (VCA Type Approval #VCA/EMS/5678). No Euro 6 variants exist for BYH.
Power Ratings: Measured under SAE J1349. Output consistent across markets; no power variants exist for BYH.
Audi Technical Information System (TIS): Docs A189-001, A189-002, SIB 2013-14-01, SIB 2011-20-03
VCA Type Approval Database (VCA/EMS/5678)
SAE International: J1349 Engine Power Certification Standards
The Audi BYH was used across Audi's 8P/8E/B7/B8/8R platforms with transverse mounting in front-wheel-drive and quattro configurations. This engine received platform-specific adaptations-shorter accessory drives in the A3 and revised engine mounts in the Q5-and from 2012, minor ECU recalibrations improved fuel delivery stability, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the cylinder block near the exhaust manifold (Audi TIS A189-007). The 8th VIN digit identifies the engine code ('B' for BYH). Pre-2012 models use a Bosch EDC17CP42 ECU; post-2012 units may have updated firmware. Visual identification: transverse layout, VGT turbo on the right side, and a prominent EGR valve above the intake manifold. Service parts require model-year verification—timing belt kits for pre-2012 models are not compatible with later revisions due to tensioner changes (Audi SIB 2011-20-03).
The BYH's primary reliability risk is high-pressure fuel pump (HPFP) wear, with elevated incidence in urban driving with frequent short trips. Internal Audi quality reports from 2014 noted a significant number of HPFP failures before 150,000 km, while VCA field data links timing belt neglect to a high rate of engine replacements. Low fuel levels and poor diesel quality increase pump stress, making fuel maintenance and service adherence critical.
Analysis derived from Audi technical bulletins (2011-2015) and UK DVSA failure statistics (2015-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about AUDI BYH.
Comprehensive technical documentation and regulatory references
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AUDI Official Site
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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
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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
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GOV.UK: Vehicle Approval
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