The Vauxhall Z18XEL is a 1,796 cc, inline‑four naturally aspirated petrol engine produced between 2006 and 2012. It features a double overhead camshaft (DOHC), 16‑valve layout with sequential multi‑point fuel injection and an aluminium block with cast‑iron cylinder liners. In standard form it delivered 92 kW (125 PS) and 165 Nm of torque, providing balanced urban agility and relaxed motorway cruising.
Fitted primarily to the Astra H, Zafira B, and Vectra C models—including the 1.8 variants—the Z18XEL was engineered for everyday reliability and low-cost maintenance. Emissions compliance was achieved through a three‑way catalytic converter and electronic throttle control, meeting Euro 4 standards across all production years.
One documented concern is premature failure of the camshaft position sensor due to exposure to engine vibration, highlighted in Vauxhall Service Information Bulletin SIB 07‑019. The sensor’s mounting location near the timing cover leads to connector fatigue and signal loss, causing intermittent misfires or no-start conditions.
All production years (2006–2012) meet Euro 4 standards (VCA UK Type Approval #VCA/EMS/6754).
The Vauxhall Z18XEL is a 1,796 cc inline‑four naturally aspirated petrol engine engineered for compact and mid‑size hatchbacks and MPVs (2006–2012). It combines sequential multi‑point fuel injection with DOHC valve actuation to deliver smooth power delivery and dependable drivability. Designed to meet Euro 4 emissions standards, it balances simplicity with modern engine management.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,796 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 80.5 mm × 88.2 mm | |
| Power output | 92 kW (125 PS) | |
| Torque | 165 Nm @ 4,000 rpm | |
| Fuel system | Bosch Motronic MPFI (sequential) | |
| Emissions standard | Euro 4 | |
| Compression ratio | 10.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain‑driven camshafts | |
| Oil type | GM Dexos1 (SAE 5W‑30) | |
| Dry weight | 124 kg |
The DOHC chain-driven design provides long service life but requires GM Dexos1 (5W‑30) oil to maintain chain tensioner function and reduce wear. The camshaft position sensor is prone to vibration-induced connector failure—symptoms include intermittent misfires and P0340 codes. Replacement with revised sensor and strain relief per SIB 07‑019 is recommended on high‑mileage units. Use only RON 95 petrol to maintain emissions compliance and prevent knock under load.
Oil Specs: Requires GM Dexos1 (5W‑30) specification (Vauxhall SIB 02‑018). Supersedes ACEA A3/B4 requirements.
Emissions: Euro 4 certification applies to all Z18XEL production (2006–2012) (VCA Type Approval #VCA/EMS/6754). No Euro 5 variants exist.
Power Ratings: Measured under ISO 1585 standards. Output consistent across all model applications (Vauxhall TIS Doc. AST‑ENG‑018).
Vauxhall Technical Information System (TIS): Docs AST‑ENG‑018, SIB 07‑019, SIB 02‑018
VCA Type Approval Database (VCA/EMS/6754)
ISO 1585: Road vehicles — Engine test code
The Vauxhall Z18XEL was used across Vauxhall's Astra H, Zafira B, and Vectra C platforms with transverse mounting and no external licensing. This engine received platform-specific adaptations—revised engine mounts in the Zafira for NVH refinement and modified intake manifolds in the Vectra—and from 2008 minor ECU updates improved cold-start emissions, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the cylinder block adjacent to the timing chain cover (Vauxhall TIS AST‑ENG‑018). The 7th VIN digit is 'Z' for Z18XEL engines. All variants use a black plastic cam cover with "1.8" embossed. Critical differentiation from Z18XE: Z18XEL uses electronic throttle control (drive-by-wire) and has a camshaft position sensor on the exhaust cam; Z18XE uses cable throttle and lacks the sensor. Chain tensioner kits are interchangeable across all years.
The Z18XEL's primary reliability risk is camshaft position sensor failure due to vibration-induced connector fatigue, with elevated incidence in high-mileage or rough-road use. Vauxhall internal data from 2010 indicated over 9% of engines required sensor replacement before 100,000 km, while UK DVSA MOT records show ignition-related failures in 7% of Astra H petrols from this era. Extended service intervals and poor mounting hardware accelerate signal degradation, making sensor inspection critical during diagnostics.
Analysis derived from Vauxhall technical bulletins (2006–2012) and UK DVSA failure statistics (2012–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL Z-18-XEL.
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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