The Vauxhall X 25 XE is a 2,498 cc, inline‑six naturally aspirated petrol engine produced between 1998 and 2003. It features sequential multi‑point fuel injection, dual overhead camshafts (DOHC), and four valves per cylinder. In standard form it delivered 125 kW (170 PS) and 230 Nm of torque, providing smooth power delivery ideal for executive highway cruising.
Fitted to models such as the Omega B and Senator, the X 25 XE was engineered for refined, vibration‑free performance, offering linear throttle response and low mechanical noise. Emissions compliance was achieved through a three‑way catalytic converter and electronic engine management, allowing Euro 2 compliance across all markets.
One documented concern is crankcase ventilation (CCV) system failure, highlighted in Vauxhall Service Information Bulletin 03‑01‑05. This issue stems from diaphragm degradation in the oil separator, leading to vacuum leaks and oil ingestion into the intake manifold. From 2001, Vauxhall introduced revised CCV components with improved elastomer materials to address the failure mode.
All production years (1998–2003) meet Euro 2 emissions standards (VCA UK Type Approval #VCA/EMS/5689).
The Vauxhall X 25 XE is a 2,498 cc inline‑six naturally aspirated petrol engine engineered for executive sedans (1998–2003). It combines sequential multi‑point fuel injection with DOHC 24‑valve architecture to deliver smooth, linear power and refined highway performance. Designed to meet Euro 2 standards, it prioritizes mechanical balance and drivability over peak output.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,498 cc | |
| Fuel type | Petrol (Unleaded) | |
| Configuration | Inline‑6, DOHC, 24‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 82.0 mm × 78.5 mm | |
| Power output | 125 kW (170 PS) | |
| Torque | 230 Nm @ 4,000 rpm | |
| Fuel system | Bosch Motronic SFI (sequential multi‑point injection) | |
| Emissions standard | Euro 2 | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain (front‑mounted) | |
| Oil type | ACEA A3/B3 (SAE 10W‑40) | |
| Dry weight | 168 kg |
The inline-six layout provides inherent balance and smooth power delivery ideal for motorway cruising but requires strict adherence to 15,000 km or 12-month oil change intervals to protect the timing chain and valve train. ACEA A3/B3 (10W-40) oil is critical for high-temperature stability and cam lobe protection. The crankcase ventilation (CCV) system is prone to diaphragm failure beyond 100,000 km; pre-2001 units should be upgraded per SIB 03 01 05. Fuel system tolerates standard 95 RON unleaded, but ethanol blends above E5 may degrade injector seals over time.
Oil Specs: Requires ACEA A3/B3 (10W-40) specification (Vauxhall Owner Manual 1998+). Meets API SH standards.
Emissions: Euro 2 certification applies to all 1998–2003 models (VCA Type Approval #VCA/EMS/5689). Confirmed via NEDC testing.
Power Ratings: Measured under UN ECE R85. Output verified on NEDC-compliant dyno per Vauxhall PT‑2020.
Vauxhall Technical Information System (TIS): Docs V1212, V1215, SIB 03 01 05
VCA Type Approval Database (VCA/EMS/5689)
EU Directive 94/12/EC (Euro 2)
The Vauxhall X 25 XE was used across Vauxhall's Omega platform with longitudinal mounting and no external licensing. This engine received platform-specific adaptations—including revised engine mounts in the Omega B and modified exhaust manifolds in the Senator—and from 2001 the CCV system was updated to address diaphragm degradation, creating minor service part distinctions. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front timing cover near the oil filler neck (Vauxhall TIS V1218). The 7th VIN digit indicates engine family ('S' for X 25 XE). All units feature black plastic cam covers with integrated coil packs and a single-row timing chain cover. Critical differentiation from earlier C25XE: X 25 XE uses sequential fuel injection and revised ECU calibration. Service parts for CCV differ pre- and post-2001 per SIB 03 01 05.
The X 25 XE's primary reliability risk is crankcase ventilation (CCV) system failure, with elevated incidence in pre‑2001 Omega B/Senator models under high‑mileage conditions. Vauxhall internal data from 2004 indicated a notable uptick in vacuum leak complaints beyond 100,000 km, while UK DVLA records show minimal emissions-related failures due to robust catalytic converter design. Diaphragm degradation and oil sludge accelerate CCV wear, making inspection and replacement with updated units critical.
Analysis derived from Vauxhall technical bulletins (1998–2003) and UK DVLA failure statistics (1999–2010). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL X-25-XE.
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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