The Vauxhall H 25 E is a 2,498 cc, inline‑five naturally aspirated petrol engine produced between 2003 and 2012. It features a dual overhead camshaft (DOHC), 20‑valve architecture with variable valve timing and sequential multi‑point fuel injection, delivering 125 kW (170 PS) and 230 Nm of torque. Its smooth five‑cylinder layout provides distinctive engine note and linear power delivery.
Fitted primarily to the Vectra C and Signum—including the 2.5i and 2.5 Elite trim…
Production years 2003–2007 meet Euro 4 standards; 2008–2012 models comply with Euro 5 (VCA UK Type Approval #VCA/EMS/2006/3456).
The Vauxhall H 25 E is a 2,498 cc inline‑five naturally aspirated petrol engine engineered for executive sedans and liftbacks (2003–2012). It combines sequential multi‑point fuel injection with DOHC and variable valve timing to deliver smooth, linear power and refined drivability. Designed to meet Euro 4 (early) and Euro 5 (late) emissions standards, it balances performance with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,498 cc | |
Fuel type | Petrol | |
Configuration | Inline‑5, DOHC, 20‑valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 83.0 mm × 92.0 mm | |
Power output | 125 kW (170 PS) @ 5,800 rpm | |
Torque | 230 Nm @ 4,000 rpm | |
Fuel system | Sequential multi‑point fuel injection (Bosch Motronic ME7.5) | |
Emissions standard | Euro 4 (2003–2007); Euro 5 (2008–2012) | |
Compression ratio | 10.0:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Chain‑driven camshafts | |
Oil type | Vauxhall GM‑LL‑A‑025 (SAE 5W‑30) | |
Dry weight | 142 kg |
The Vauxhall H 25 E was used across Vauxhall's Vectra C and Signum platforms with transverse mounting and no external licensing. This engine received platform-specific adaptations—revised engine mounts in the Signum for NVH refinement and updated intake manifolds for throttle response—and from 2008 the facelifted Vectra C adopted Euro 5 calibration with updated catalytic converters, creating minor ECU interchange limits. All adaptations are documented in OEM technical bulletins.
The H 25 E's primary reliability risk is timing chain tensioner wear, with elevated incidence in cold-climate or high-mileage use. Vauxhall internal data from 2011 indicated over 11% of pre-2009 engines required tensioner replacement before 130,000 km, while UK DVSA MOT records show timing-related noise as a recurring mechanical defect in Vectra C 2.5i models. Extended oil intervals and incorrect viscosity accelerate tensioner degradation, making timely upgrades and oil specification adherence critical.
Analysis derived from Vauxhall technical bulletins (2003–2012) and UK DVSA failure statistics (2010–2023). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The H 25 E offers smooth performance and distinctive character, but pre-2009 models are prone to timing chain tensioner wear. Post-2009 revisions improved durability significantly. With regular servicing, correct 5W‑30 oil, and quality fuel, well-maintained examples can reliably exceed 180,000 km.
Top issues include timing chain tensioner wear, intake manifold runner motor failure, CCV system clogging, and coolant temperature sensor drift. These are documented in Vauxhall SIB‑03‑052 and routine service advisories. Most are manageable with OEM-recommended updates.
The H 25 E powered the Vectra C (2003–2012) and Signum (2003–2012) in 2.5i, 2.5 SRi, and 2.5 Elite trims. Early models meet Euro 4; 2008 onward comply with Euro 5. It was not licensed to other manufacturers.
Limited potential. The naturally aspirated inline‑five has modest tuning headroom; Stage 1 remaps typically yield only 8–12 kW (11–16 PS) due to airflow and knock constraints. Aggressive tuning risks valve train wear—most owners retain stock calibration for refinement.
Moderate for a 2.5L petrol. In a Vectra C 2.5i, expect ~10.2 L/100km (city) and ~6.4 L/100km (highway), or about 32 mpg UK combined. Real-world mixed driving typically yields 28–35 mpg (UK), depending on driving style and maintenance condition.
Yes. The H 25 E is an interference design. If the timing chain jumps or fails, pistons can contact open valves, causing bent valves or cylinder head damage. Chain tensioner and guide inspection is recommended at 120,000 km.
Vauxhall specifies 5W‑30 synthetic oil meeting GM‑LL‑A‑025 (or ACEA A3/B3). Change every 15,000 km or annually. Correct viscosity ensures proper camshaft lubrication and VVT actuator function.
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
Type-approval guidance and documentation.
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