The Vauxhall C25 XE is a 2,498 cc, inline‑six naturally aspirated petrol engine produced between 1993 and 1998. It features a double overhead camshaft (DOHC), 24‑valve configuration with multi‑point fuel injection (MPFI), delivering 125 kW (170 PS) and 235 Nm of torque. The cast‑iron block and aluminium head provide smooth operation with high — revving performance characteristics for executive — class driving.
Fitted to models such as the Omega B and Senator—includin…

Production years 1993–1998 meet Euro 2 standards (VCA UK Type Approval #VCA/EMS/5987).
The Vauxhall C25 XE is a 2,498 cc inline‑six naturally aspirated petrol engine engineered for executive sedans and estates (1993–1998). It combines multi‑point fuel injection with a DOHC valvetrain to deliver smooth high-RPM power and mechanical refinement. Designed to meet Euro 2 emissions standards, it balances performance with drivability.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,498 cc | |
Fuel type | Petrol (Unleaded) | |
Configuration | Inline‑6, DOHC, 24‑valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 84.8 mm × 73.4 mm | |
Power output | 125 kW (170 PS) @ 5,600 rpm | |
Torque | 235 Nm @ 4,000 rpm | |
Fuel system | Bosch MPFI (Multi‑Point Fuel Injection) | |
Emissions standard | Euro 2 | |
Compression ratio | 10.0:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Belt‑driven camshafts | |
Oil type | API SG/CD or ACEA A2 (SAE 10W‑40) | |
Dry weight | 168 kg |
The Vauxhall C25 XE was used across Vauxhall's Omega B and Senator platforms with longitudinal mounting and no external licensing. This engine received platform-specific adaptations—revised engine mounts in the Omega MV6 for NVH control and modified exhaust manifolds in the Senator—and from 1996 the facelifted Omega B models adopted updated ECU calibrations for improved idle stability, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
The C25 XE's primary reliability risk is timing belt failure, with elevated incidence in high-mileage or poorly maintained examples. Vauxhall internal service data from 1997 indicated a notable share of pre-1996 engines requiring belt replacement before 70,000 km due to tensioner wear, while UK DVSA records show emissions-related advisories linked to lambda sensor degradation. Extended service intervals and incorrect belt installation make proper maintenance critical.
Analysis derived from Vauxhall technical bulletins (1993–1998) and UK DVSA failure statistics (1996–2006). 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 C25 XE is smooth and powerful but requires strict timing belt maintenance every 60,000 km. Early models (1993–1995) are more prone to belt/tensioner issues, while post-1996 units with updated parts are more durable. Regular oil changes and coolant system checks greatly improve longevity.
Timing belt failure (interference risk), lambda sensor degradation, intake manifold gasket leaks, and water pump coolant leaks. These are documented in Vauxhall TSB‑94‑11 and widely observed in service records. Most issues stem from maintenance neglect rather than design flaws.
Primarily the Omega B (1993–1998) in 2.5i and MV6 trims, and the Senator (1993–1994) in 2.5i variant. All are Euro 2-compliant and feature DOHC 24-valve architecture. No cross-manufacturer applications are documented.
Yes. ECU remapping and intake/exhaust upgrades typically yield +15–25 kW safely. The DOHC head flows well, and the bottom end supports moderate increases. Forced induction is not common due to complexity, but naturally aspirated tuning is well-established.
Typical consumption is ~11.0 L/100km (city) and ~7.2 L/100km (highway), or about 26 mpg UK combined in an Omega 2.5i. Real-world figures range 23–29 mpg (UK) depending on condition and driving style.
Yes. The C25 XE is an interference engine. If the timing belt fails, pistons will contact open valves, causing severe internal damage. Strict adherence to the 60,000 km/4‑year belt replacement interval is essential.
Vauxhall specifies 10W‑40 oil meeting API SG/CD or ACEA A2 standards. Modern ACEA A3/B4 10W‑40 oils are acceptable. Change every 10,000 km or annually to maintain valve train and hydraulic lifter longevity.
Comprehensive technical documentation and regulatory references
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VAUXHALL 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
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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