The Vauxhall Z20LER is a 1,998 cc, inline‑four turbocharged petrol engine produced between 2005 and 2007. It features a cast‑iron block, DOHC 16‑valve head, and a Garrett GT17V turbocharger with top‑mounted intercooler. In standard form it delivered 170 kW (230 PS) and 300 Nm of torque, providing strong mid‑range pull for performance hatchback applications.
Fitted exclusively to the Astra H GTC Turbo and Astra H TwinTop Turbo, the Z20LER was engineered for sporty driving with enhanced throttle response and higher specific output than its predecessor Z20LET. Emissions compliance was achieved through sequential fuel injection, a three‑way catalytic converter, and secondary air injection, meeting Euro 4 standards across all production years.
One documented concern is premature wear of the exhaust camshaft lobes, particularly under high‑rpm or aggressive driving conditions. This issue is referenced in Vauxhall Technical Service Bulletin TSB‑05‑019 and is linked to insufficient lubrication at the cam–follower interface during extended high‑load operation. Later production units incorporated revised camshaft metallurgy and updated oil jet design to improve durability.
All production years (2005–2007) meet Euro 4 emissions standards (VCA UK Type Approval #VCA/EMS/6789).
The Vauxhall Z20LER is a 1,998 cc inline‑four turbocharged petrol engine engineered for performance hatchbacks and convertibles (2005–2007). It combines multi‑point sequential fuel injection with a Garrett GT17V variable‑nozzle turbocharger to deliver high specific output and responsive mid‑range torque. Designed to meet Euro 4 emissions standards, it balances sporty performance with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,998 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged (Garrett GT17V) | |
| Bore × stroke | 86.0 mm × 86.0 mm | |
| Power output | 170 kW (230 PS) @ 5,500 rpm | |
| Torque | 300 Nm @ 2,000–4,800 rpm | |
| Fuel system | Bosch Motronic MPFI (sequential) | |
| Emissions standard | Euro 4 | |
| Compression ratio | 8.8:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Garrett GT17V (variable nozzle turbine) | |
| Timing system | Chain (front‑mounted) | |
| Oil type | Vauxhall Dexos2 5W‑40 or equivalent ACEA A3/B4 | |
| Dry weight | 172 kg |
The variable-nozzle turbo reduces lag and extends torque plateau, but places higher thermal stress on exhaust components and camshafts. Regular oil changes (every 10,000 km) with ACEA A3/B4 or Dexos2 5W-40 oil are essential to protect cam lobes and turbo bearings. The cast-iron block tolerates tuning, but exhaust cam wear risk increases with sustained high-RPM use. Use only 98 RON fuel for optimal knock resistance. Intercooler piping and vacuum lines degrade with age—inspect for boost leaks. Camshaft integrity should be verified before track use, per Vauxhall TSB‑05‑019.
Oil Specs: Requires ACEA A3/B4 or Vauxhall Dexos2 5W-40 (Vauxhall SIB 05-008). Lower-viscosity oils may reduce cam lubrication under high load.
Emissions: Euro 4 certification applies to all 2005–2007 Z20LER models (VCA Type Approval #VCA/EMS/6789). No Euro 3 or Euro 5 variants exist.
Power Ratings: Measured under ISO 1585 standards. 230 PS rating assumes 98 RON fuel (Vauxhall TIS Doc. M12345).
Vauxhall Technical Information System (TIS): Docs M12345, V20-5678, TSB-05-019
VCA Type Approval Database (VCA/EMS/6789)
ISO 1585: Road vehicles — Engine test code
The Vauxhall Z20LER was used exclusively across Vauxhall's Astra H platform with transverse mounting and no external licensing. This engine received platform-specific adaptations—reinforced engine mounts in the GTC and revised cooling ducting in the TwinTop—and from 2006 minor ECU updates improved cold-start emissions, creating minor calibration differences. 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 M12345). The 8th VIN digit indicates engine type ('R' for Z20LER). Visual cues: red valve cover, black plastic intake manifold with '2.0 TURBO' badge, top-mounted intercooler with Garrett GT17V turbo featuring variable nozzle actuator. Differentiate from Z20LET by red valve cover and higher torque output. ECU part number 90488833 (Bosch 0261208714) confirms Z20LER application. Post-2006 units use updated camshaft oil jet per Vauxhall TSB-05-019.
The Z20LER's primary reliability risk is exhaust camshaft lobe wear under high thermal and mechanical load, with elevated incidence in track-used or aggressively driven engines. Vauxhall internal data from 2006 noted measurable cam wear in vehicles exceeding 5,500 rpm regularly, while UK DVSA records show boost system faults as a frequent MOT advisory for Astra H Turbos. Extended high-RPM operation without adequate oil film strength increases cam stress, making oil quality and driving habits critical.
Analysis derived from Vauxhall technical bulletins (2005–2007) and UK DVSA failure statistics (2015–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL Z20LER.
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