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—including the 2.5i and MV6 variants—the C25 XE was engineered for refined motorway cruising and spirited driving dynamics. Emissions compliance was achieved through a three‑way catalytic converter and closed‑loop lambda control, meeting Euro 2 standards throughout its production run.
One documented concern is timing belt failure due to extended service intervals or tensioner wear, highlighted in Vauxhall Technical Service Bulletin TSB‑94‑11. This is often linked to inadequate lubrication of auxiliary components or incorrect belt routing during prior servicing. Later production units incorporated revised tensioner materials and updated replacement intervals.
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 DOHC inline‑six layout provides inherent balance and high-RPM smoothness but requires strict adherence to 60,000 km timing belt replacement intervals with correct tensioner inspection. Extended intervals or improper installation risk catastrophic interference damage. Fuel must meet EN 228 standards; ethanol blends above E5 may degrade seals over time. Oil changes every 10,000 km with ACEA A2 or API SG oil help preserve valve train longevity. Valve clearance checks are not required due to hydraulic lifters, but carbon buildup on intake valves may occur over time.
Oil Specs: Requires API SG/CD or ACEA A2 (10W‑40) specification (Vauxhall Owner Manual 1994). Modern ACEA A3/B4 oils are acceptable if viscosity matches.
Emissions: Euro 2 certification applies to all 1993–1998 C25 XE units (VCA Type Approval #VCA/EMS/5987). No Euro 1 or Euro 3 variants produced.
Power Ratings: Measured under ISO 1585 standards. Output verified on dynamometer per Vauxhall PT‑1995.
Vauxhall Technical Information System (TIS): Docs V93‑155, V94‑088
Vauxhall Technical Service Bulletins: TSB‑94‑11
VCA Type Approval Database (VCA/EMS/5987)
ISO 1585: Road vehicles — Engine test code
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.
Locate the engine code stamped on the front face of the cylinder block near the timing cover (Vauxhall TIS V93‑155). The 8th VIN digit indicates engine displacement ('5' for 2.5L). C25 XE units feature a black plastic intake manifold with “25i” moulded into the plenum and a Bosch MPFI rail. Critical differentiation from A24 XF: C25 XE uses DOHC with 24 valves and a timing belt; A24 XF is SOHC with 12 valves and a chain. ECU part numbers beginning with “25XE” confirm application.
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.
Find answers to most commonly asked questions about VAUXHALL C-25-XE.
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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
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DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
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
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
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