The Vauxhall Z20LEH is a 1,998 cc, inline‑four turbocharged petrol engine produced between 2005 and 2008. It features a dual‑overhead camshaft (DOHC) layout, variable valve timing (VVT), and a Garrett GT17V turbocharger. In standard form it delivered 174 kW (240 PS) and 320 Nm of torque, enabling strong performance while meeting Euro 4 emissions standards.
Fitted exclusively to the Vectra OPC (VXR in the UK), the Z20LEH was engineered for high‑performance driving with everyday usability. Emissions compliance was achieved through a three‑way catalytic converter and precise electronic engine management, allowing the engine to meet Euro 4 standards across all production years.
One documented concern is premature failure of the plastic inlet manifold, which can crack under thermal stress or boost pressure. This issue, highlighted in Vauxhall Technical Service Bulletin TSB-05-08-012, is linked to material fatigue in high‑load conditions. Later service replacements used a reinforced composite manifold to address the defect.
Production years 2005–2008 meet Euro 4 standards (VCA UK Type Approval #VCA/EMS/5678).
The Vauxhall Z20LEH is a 1,998 cc inline‑four turbocharged petrol engineered for high‑performance mid‑size sedans (2005–2008). It combines DOHC with variable valve timing and a single turbocharger to deliver responsive power and strong mid‑range torque. Designed to meet Euro 4 standards, it balances track‑capable output with daily usability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,998 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 86.0 mm × 86.0 mm | |
| Power output | 174 kW (240 PS) @ 5,600 rpm | |
| Torque | 320 Nm @ 2,200–4,800 rpm | |
| Fuel system | Bosch ME7.8.8 multi‑point sequential injection | |
| Emissions standard | Euro 4 | |
| Compression ratio | 8.8:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Garrett GT17V (single, wastegate‑controlled) | |
| Timing system | Chain (front‑mounted) | |
| Oil type | GM Dexos2 (SAE 5W‑30) | |
| Dry weight | 168 kg |
The turbocharged Z20LEH delivers brisk acceleration and a wide torque band but requires strict adherence to 10,000 km oil change intervals using GM Dexos2 (5W‑30) to protect turbo bearings and timing chain. The plastic inlet manifold is prone to cracking under high boost or thermal cycling; replacement with the revised composite unit (P/N 55358915) per TSB-05-08-012 is recommended. High‑quality 98 RON fuel optimizes performance and reduces knock risk. Intercooler and boost hoses should be inspected regularly for leaks affecting boost control.
Oil Specs: Requires GM Dexos2 (5W‑30) specification (Vauxhall TSB-05-08-012). Meets ACEA C3 but with GM-specific additive limits.
Emissions: Euro 4 certification applies to all 2005–2008 Z20LEH engines (VCA Type Approval #VCA/EMS/5678).
Power Ratings: Measured under ISO 1585 standards. Peak output assumes 98 RON fuel (Vauxhall TIS Doc. V30210).
Vauxhall Technical Information System (TIS): Docs V30125, V30126, V30210, TSB-05-08-012
VCA Type Approval Database (VCA/EMS/5678)
ISO 1585: Road vehicles – Engine test code
The Vauxhall Z20LEH was used exclusively in Vauxhall's Vectra C platform with longitudinal mounting and no cross‑manufacturer licensing. This engine received platform-specific adaptations—reinforced subframe mounts and a high-capacity intercooler—and from 2007 minor ECU updates improved throttle response, though mechanical compatibility remained consistent. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front timing cover near the crank pulley (Vauxhall TIS V30125). The 7th VIN digit for Z20LEH-equipped Vectra OPC is 'H'. Visual identification: black plastic inlet manifold (pre-TSB) or grey composite (post-TSB), red valve cover, and OPC-specific intercooler piping. Critical differentiation from non-turbo Z20NET: Z20LEH has a Garrett turbo, twin-pipe exhaust manifold, and higher-flow fuel injectors. Service parts require production date verification—manifolds before 06/2006 are incompatible with later ECU calibrations due to boost control differences (Vauxhall TSB-05-08-012).
The Z20LEH's primary reliability risk is inlet manifold cracking on early builds, with elevated incidence in high-load or track use. Vauxhall internal data from 2007 indicated a significant number of pre-2006 manifolds required replacement before 80,000 km, while UK DVSA records show minimal emissions-related failures due to robust catalytic converter design. Aggressive driving and poor-quality fuel increase knock and thermal stress, making fuel grade and service adherence critical.
Analysis derived from Vauxhall technical bulletins (2005-2009) and UK DVSA failure statistics (2015-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL VECTRA-OPC.
Comprehensive technical documentation and regulatory references
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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
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