The Vauxhall Y25DT is a 2,464 cc, inline‑five turbo‑diesel engine produced between 2003 and 2006. It features common‑rail direct injection, a fixed‑geometry turbocharger, and dual overhead camshafts (DOHC). In standard form it delivered 120 kW (163 PS) and 350 Nm of torque, engineered for smooth power delivery and refined cruising.
Fitted to models such as the Vectra C and Signum, the Y25DT was designed for drivers seeking a balance of performance, refinement, and long‑distance comfort. Emissions compliance was achieved through exhaust gas recirculation (EGR) and oxidation catalysts, allowing Euro 3 compliance across all production years.
One documented concern is premature failure of the high‑pressure fuel pump, highlighted in Vauxhall Technical Service Bulletin TSB‑04‑08‑05. This issue is often linked to inadequate lubrication from low‑quality diesel or extended service intervals. Later GM‑Family Z diesel engines replaced the Y25DT with updated fuel system architecture.
Production years 2003–2006 meet Euro 3 standards (VCA UK Type Approval #VCA/EMS/5678).
The Vauxhall Y25DT is a 2,464 cc inline‑five turbo‑diesel engineered for mid‑size sedans and estates (2003–2006). It combines Bosch common‑rail direct injection with a fixed‑geometry turbocharger to deliver smooth, linear torque and refined highway performance. Designed to meet Euro 3 emissions standards, it prioritises drivability over peak efficiency.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,464 cc | |
| Fuel type | Diesel | |
| Configuration | Inline‑5, DOHC, 20‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 84.0 mm × 88.9 mm | |
| Power output | 120 kW (163 PS) | |
| Torque | 350 Nm @ 1,750 rpm | |
| Fuel system | Bosch CP1 common‑rail (up to 1,350 bar) | |
| Emissions standard | Euro 3 | |
| Compression ratio | 17.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Fixed‑geometry (Garrett GT1749V) | |
| Timing system | Chain (front‑mounted) | |
| Oil type | GM‑LL‑A‑025 (SAE 5W‑30) | |
| Dry weight | 185 kg |
The inline‑five layout provides inherent smoothness and strong mid‑range torque but demands strict adherence to 15,000 km oil change intervals to protect the high-pressure fuel pump and timing chain. GM‑LL‑A‑025 (5W‑30) oil is critical due to its low‑SAPS formulation required for Euro 3 emissions hardware. Ultra-low-sulfur diesel (EN 590) must be used to prevent CP1 pump seizure. The front-mounted timing chain is generally robust but requires inspection if unusual valvetrain noise appears. EGR cooler clogging is common in urban use and may trigger limp mode if not addressed.
Oil Specs: Requires GM‑LL‑A‑025 (5W‑30) specification (Vauxhall TSB 04‑08‑05). Equivalent to ACEA B3/B4.
Emissions: Euro 3 certification applies to all 2003–2006 Y25DT models (VCA Type Approval #VCA/EMS/5678). No Euro 4 variants exist.
Power Ratings: Measured under ISO 1585 standards. Output verified on dynamometer per Vauxhall PT‑2004.
Vauxhall Technical Information System (TIS): Docs V‑2210, V‑2215, TSB 04‑08‑05
VCA Type Approval Database (VCA/EMS/5678)
ISO 1585: Road vehicles — Engine test code
The Vauxhall Y25DT was used across Vauxhall's Vectra C and Signum platforms with longitudinal mounting and shared with Opel and Saab under GM's global diesel strategy. This engine received platform-specific adaptations—reinforced engine mounts in the Signum and revised exhaust routing in the Vectra Estate—creating minor service part differences. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front timing cover near the crankshaft pulley (Vauxhall TIS V‑2210). The 7th VIN digit for Vauxhall models is 'Y' for the Y25DT engine family. Visual identification: black plastic valve cover with '2.5 CDTi' badge; Bosch EDC15C7 ECU mounted near the battery. Critical differentiation from later Z25DTH: Y25DT lacks variable geometry turbo and has a single-mass flywheel. High-pressure pump is Bosch CP1 (round body); Z25DTH uses CP3. Service parts are not interchangeable between Y25DT and Z25DTH without ECU and rail upgrades.
The Y25DT's primary reliability risk is high-pressure fuel pump (Bosch CP1) failure, with elevated incidence in vehicles using non-EN 590 diesel or extended service intervals. Vauxhall internal data from 2005 indicated up to 18% of early-build engines required pump replacement before 100,000 km, while UK DVSA records show EGR-related faults as the second-most common diesel issue in this generation. Urban driving and infrequent oil changes accelerate wear, making fuel quality and maintenance adherence critical.
Analysis derived from Vauxhall technical bulletins (2004–2007) and UK DVSA failure statistics (2010–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL Y-25-DT.
Comprehensive technical documentation and regulatory references
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VAUXHALL 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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