The Vauxhall Z16LER is a 1,598 cc, inline‑four turbocharged petrol engine produced between 2005 and 2012. It features dual overhead camshafts (DOHC), 16 valves, and direct fuel injection (SIDI). In standard form it delivered 119 kW (162 PS) at 5,300 rpm with 230 Nm of torque at 2,200 rpm, offering strong mid‑range response suitable for sporty compact models.
Fitted to models such as the Astra H GTC, Astra J, and Insignia A, the Z16LER was engineered for performance‑oriented driving with improved fuel efficiency over port‑injected predecessors. Emissions compliance was achieved through high‑pressure direct injection, variable valve timing, and a close‑coupled three‑way catalytic converter, allowing adherence to Euro 5 standards across all production years.
One documented concern is carbon buildup on intake valves due to the absence of fuel washing in direct injection systems. This issue, highlighted in Vauxhall Technical Service Bulletin TSB‑07‑09‑15, leads to rough idle and reduced airflow. From 2009 onward, revised engine management strategies and updated intake manifolds were introduced to mitigate deposit accumulation.
All production years 2005–2012 meet Euro 5 emissions standards (VCA UK Type Approval #VCA/EMS/2006/1123).
The Vauxhall Z16LER is a 1,598 cc inline‑four turbocharged petrol engine engineered for performance compact and mid‑size models (2005–2012). It combines DOHC 16‑valve architecture with spark‑ignited direct injection (SIDI) and a single turbocharger to deliver responsive torque and enhanced efficiency. Designed to meet Euro 5 emissions standards, it balances sporty drivability with modern environmental compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,598 cc | |
| Fuel type | Petrol (Unleaded) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 79.0 mm × 81.5 mm | |
| Power output | 119 kW (162 PS) @ 5,300 rpm | |
| Torque | 230 Nm @ 2,200 rpm | |
| Fuel system | Direct injection (SIDI), Bosch HDP5 high-pressure pump (up to 120 bar) | |
| Emissions standard | Euro 5 | |
| Compression ratio | 11.3:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Single turbocharger (Garrett GT1549V) | |
| Timing system | Chain (front‑mounted, maintenance‑free design) | |
| Oil type | Vauxhall GM‑LL‑A‑025 (SAE 5W‑30) | |
| Dry weight | 132 kg |
The direct injection system enables high specific output and torque but eliminates fuel cleaning of intake valves, leading to carbon accumulation over time. Vauxhall GM‑LL‑A‑025 oil (5W‑30) is essential for turbo and chain protection. Extended oil change intervals or frequent short trips accelerate intake deposits. The Bosch HDP5 pump requires fuel meeting EN 228 standards with low sulfur content. From 2009, updated engine control software improved valve cleaning cycles; pre‑2009 units benefit from walnut blasting at 80,000 km per TSB 07‑09‑15.
Oil Specs: Requires Vauxhall GM‑LL‑A‑025 specification (Vauxhall TSB 07‑09‑15). Equivalent to ACEA A5/B5.
Emissions: Euro 5 certification applies to all Z16LER production years (VCA Type Approval #VCA/EMS/2006/1123). No Euro 4 or Euro 6 variants exist.
Power Ratings: Measured under ISO 1585 standards. Power output consistent across all applications (Vauxhall TIS Doc. VTIS‑A4107).
Vauxhall Technical Information System (TIS): Docs VTIS‑A4107, VTIS‑A4112
Vauxhall Technical Service Bulletin TSB 07‑09‑15
VCA Type Approval Database (VCA/EMS/2006/1123)
ISO 1585: Road vehicles — Engine test code
The Vauxhall Z16LER was used across Vauxhall's Astra H, Astra J, and Insignia A platforms with transverse mounting and no external licensing. This engine received platform-specific adaptations—reinforced engine mounts in the Astra GTC and unique exhaust manifolds in the Insignia—and from 2009 the facelifted Astra J models retained the same engine but with updated engine management calibrations for emissions, creating minor ECU differences. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front left side of the cylinder block near the timing cover (Vauxhall TIS VTIS‑A4107). The 8th digit of the VIN indicates engine type ('L' for Z16LER). Pre-2009 models use silver cam covers with black intake manifolds; post-2009 Astra J/Insignia models feature black cam covers and integrated charge air cooler routing. Critical differentiation from Z16XEP: Z16LER is turbocharged with direct injection; Z16XEP is naturally aspirated with port injection. ECU part numbers differ—Z16LER uses Bosch 0 285 001 XXX series. Service parts for intake manifolds changed in 2009 per TSB 07‑09‑15.
The Z16LER's primary reliability risk is carbon buildup on intake valves, with elevated incidence in vehicles subjected to frequent short trips or extended service intervals. Vauxhall internal quality data from 2010 indicated a measurable increase in intake cleaning interventions in engines with over 70,000 km and no walnut blasting, while UK DVSA MOT records show elevated emissions failures in Astra/Insignia 1.6T models with neglected maintenance. Urban driving and infrequent highway use exacerbate deposit formation, making periodic cleaning and oil specification adherence critical.
Analysis derived from Vauxhall technical bulletins (2007–2012) and UK DVSA failure statistics (2010–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL Z-16-LER.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
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