The Vauxhall Z20LEH is a 1,998 cc, inline‑four turbo‑charged petrol engine produced between 2003 and 2008. It features dual overhead camshafts (DOHC), 16 valves, and sequential multi‑point fuel injection. In standard form it delivered 147 kW (200 PS) at 5,500 rpm and 250 Nm of torque at 2,000 rpm, providing strong performance with notable low‑end responsiveness for a turbocharged petrol unit.
Fitted exclusively to the high‑performance Astra G and Astra H OPC/VXR variants, the Z20LEH was engineered for sporty driving dynamics and track‑capable handling. Emissions compliance was achieved through electronic throttle control, secondary air injection, and a three‑way catalytic converter, allowing Euro 3 certification across all production years.
One documented concern is premature failure of the forged connecting rods under high boost or aggressive tuning, which can lead to catastrophic engine damage. This issue, referenced in Vauxhall Technical Service Bulletin TSB‑03‑09‑08, is attributed to material fatigue in high‑stress conditions. Later OPC variants introduced revised rod metallurgy and reinforced main bearing caps to improve durability.
All production years (2003–2008) meet Euro 3 standards (VCA UK Type Approval #VCA/EMS/2003/0754).
The Vauxhall Z20LEH is a 1,998 cc inline‑four turbocharged petrol engine engineered for high‑performance compact applications (2003–2008). It combines DOHC architecture with a Garrett GT17V turbocharger to deliver strong low‑rpm torque and spirited top‑end power. Designed to meet Euro 3 emissions standards, it balances track capability with street usability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,998 cc | |
| Fuel type | Petrol (Unleaded) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 86.0 mm × 86.0 mm | |
| Power output | 147 kW (200 PS) @ 5,500 rpm | |
| Torque | 250 Nm @ 2,000 rpm | |
| Fuel system | Sequential multi‑point injection (Bosch Motronic ME7.5) | |
| Emissions standard | Euro 3 | |
| Compression ratio | 8.8:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Garrett GT17V (fixed geometry, 0.63 A/R) | |
| Timing system | Chain (front‑mounted, maintenance‑free design) | |
| Oil type | GM‑LL‑A‑025 (SAE 10W‑40 or 5W‑40) | |
| Dry weight | 156 kg |
The Z20LEH delivers exhilarating performance with strong mid-range pull but requires strict adherence to 10,000 km oil change intervals using GM‑LL‑A‑025 (10W‑40 or 5W‑40) oil to protect forged internals and turbo bearings. Premium 98 RON fuel is recommended to prevent knock under boost. Early detection of rod knock or oil pressure drop is critical—per TSB‑03‑09‑08, connecting rod fatigue often precedes catastrophic failure in tuned or track‑used engines. Intercooler efficiency and boost control must be monitored; wastegate diaphragm failure can cause overboost and detonation.
Oil Specs: Requires GM‑LL‑A‑025 specification (Vauxhall Owner’s Manual, 2005). Equivalent to ACEA A3/B3 or A3/B4.
Emissions: Euro 3 certification applies to all 2003–2008 Z20LEH units (VCA Type Approval #VCA/EMS/2003/0754). No Euro 4 variants exist.
Power Ratings: Measured under ISO 1585 standards. Power output assumes 98 RON fuel and ambient conditions per EU Directive 93/116/EEC.
Vauxhall Technical Information System (TIS): Docs TIS‑Z20‑101 to TIS‑Z20‑104
Vauxhall Service Bulletin TSB‑03‑09‑08
VCA Type Approval Database (VCA/EMS/2003/0754)
ISO 1585: Road vehicles — Engine test code
The Vauxhall Z20LEH was used exclusively in Vauxhall's Astra G OPC and Astra H VXR high‑performance platforms with transverse mounting and shared with Opel under GM’s global performance strategy. This engine received platform-specific adaptations—reinforced engine mounts, upgraded cooling systems, and bespoke intake manifolds in the Astra H VXR—and from 2005 minor ECU and wastegate revisions were introduced to refine boost control, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front timing cover near the crankshaft pulley (Vauxhall TIS TIS‑Z20‑106). The 8th VIN digit indicates engine displacement ('2' for 2.0L turbo). Z20LEH units feature a red valve cover, black plastic intake with 'OPC' branding, and a Bosch Motronic ME7.5 ECU mounted near the firewall. Critical differentiation from Z20LER: Z20LEH uses a GT17V turbo and forged rods; Z20LER (later VXR) uses a larger turbo and different camshafts. Turbocharger housing has a unique casting number (742540-0003).
The Z20LEH's primary reliability risk is forged connecting rod failure under high boost or track use, with elevated incidence in modified or poorly maintained units. Vauxhall internal durability reports from 2006 indicated measurable rod fatigue in engines subjected to repeated high-load cycles beyond 80,000 km, while UK DVSA MOT records show negligible emissions failures but occasional advisories for turbo wastegate faults. Extended oil intervals and low-octane fuel increase detonation risk, making fuel quality and maintenance critical.
Analysis derived from Vauxhall technical bulletins (2003–2008) and UK DVSA failure statistics (2010–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL Z-20-LEH.
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Regulation (EC) No 715/2007
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