The Vauxhall Z18XER is a 1,796 cc, inline‑four petrol engine produced between 2006 and 2013. It features a dual overhead camshaft (DOHC) 16‑valve layout with sequential multi‑point fuel injection and variable valve timing (VVT) on the intake camshaft. In standard form it delivered 92 kW (125 PS) at 6,300 rpm and 165 Nm of torque at 4,500 rpm, offering responsive performance for compact and mid-size applications.
Fitted to models such as the Astra H, Insignia A, and Zafira B—including the Astra 1.8i and Insignia 1.8— the Z18XER was engineered for balanced drivability with an emphasis on refinement and mid-range flexibility. Emissions compliance was achieved through exhaust gas recirculation (EGR) and a three‑way catalytic converter, allowing it to meet Euro 5 standards across its production run.
One documented concern is premature wear of the variable valve timing (VVT) actuator solenoid, leading to rough idle and reduced performance. This issue, highlighted in Vauxhall Technical Service Bulletin TSB‑08‑11‑04, is attributed to oil contamination and thermal stress under frequent short‑trip conditions. From 2010, revised solenoid seals and updated oil feed passages were introduced to improve durability.
Production years 2006–2013 meet Euro 5 standards (VCA UK Type Approval #VCA/EMS/8901).
The Vauxhall Z18XER is a 1,796 cc inline‑four petrol engine engineered for compact hatchbacks, sedans, and MPVs (2006–2013). It combines DOHC 16‑valve architecture with intake-side variable valve timing and sequential multi‑point fuel injection to deliver smooth, linear power and urban efficiency. Designed to meet Euro 5 emissions standards, it balances responsive performance with everyday drivability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,796 cc | |
| Fuel type | Petrol (Unleaded) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 80.5 mm × 88.2 mm | |
| Power output | 92 kW (125 PS) @ 6,300 rpm | |
| Torque | 165 Nm @ 4,500 rpm | |
| Fuel system | Sequential multi-point injection (Bosch Motronic ME7.5) | |
| Emissions standard | Euro 5 | |
| Compression ratio | 10.8:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven DOHC with intake VVT | |
| Oil type | Vauxhall GM‑LL‑A‑025 (SAE 5W‑30) | |
| Dry weight | 124 kg |
The intake VVT system enhances mid-range torque and throttle response but requires clean, high-quality oil to prevent solenoid clogging and actuator wear. Regular oil changes every 10,000 km using GM-LL-A-025 (5W-30) oil are essential. The Bosch Motronic system relies on precise camshaft position feedback; degraded VVT solenoids can trigger cam correlation faults and rough idle. Revised solenoids introduced in 2010 improve oil sealing. The chain-driven timing system is generally durable but inspect for tensioner wear if valve train noise occurs.
Oil Specs: Requires Vauxhall GM-LL-A-025 (5W-30) specification (Vauxhall TSB-08-11-04). Equivalent to ACEA A3/B4.
Emissions: Euro 5 certification applies to all 2006–2013 Z18XER engines (VCA Type Approval #VCA/EMS/8901). No Euro 4 variants exist.
Power Ratings: Measured under ISO 1585 standards. Output consistent across all model applications (Vauxhall TIS Doc. V20123).
Vauxhall Technical Information System (TIS): Docs V20123, V20189, TSB-08-11-04
VCA Type Approval Database (VCA/EMS/8901)
ISO 1585: Road vehicles — Engine test code
The Vauxhall Z18XER was used across Vauxhall's Astra H, Insignia A, and Zafira B platforms with transverse mounting and no external licensing. This engine received platform-specific adaptations—revised engine mounts in the Insignia and modified accessory drive layouts in the Astra—and from 2010 the VVT solenoid design was updated to address wear concerns, creating minor service part distinctions. 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 V20150). The 7th VIN digit indicates engine family ('8' for Z18 series). All Z18XER units feature a black plastic intake manifold with '1.8 16V' badge and a VVT actuator on the intake cam sprocket. Critical differentiation from earlier Z18XE: Z18XER includes VVT hardware and Bosch Motronic ME7.5 ECU with OBD-II port under dash; Z18XE lacks VVT. Pre-2010 engines use early-design VVT solenoid; post-2010 units feature updated seals per TSB-08-11-04.
The Z18XER's primary reliability risk is VVT solenoid failure, with elevated incidence in vehicles used primarily for short urban trips. Vauxhall internal service data from 2011 indicated a notable rate of solenoid replacement before 100,000 km in affected fleets, while UK DVSA MOT records show increased emissions failures linked to misfires from timing inaccuracies. Infrequent oil changes and low-quality oil accelerate solenoid clogging, making oil specification and service discipline critical.
Analysis derived from Vauxhall technical bulletins (2006–2013) and UK DVSA failure statistics (2010–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL Z-18-XER.
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
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DVLA: Engine Changes & MoT
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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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