The Vauxhall Z28NET is a 2,792 cc, V6 naturally aspirated petrol engine produced between 2009 and 2017. It features a double overhead camshaft (DOHC), 24‑valve layout with sequential multi‑point fuel injection and an aluminium block with cast‑iron cylinder liners. In standard form it delivered 152 kW (207 PS) and 266 Nm of torque, providing smooth, linear power delivery ideal for executive saloons and performance estates.
Fitted primarily to the Insignia A and VXR models—including the 2.8 Turbo V6 variants—the Z28NET was engineered for refined highway cruising and responsive mid‑range acceleration. Emissions compliance was achieved through a three‑way catalytic converter and electronic throttle control, meeting Euro 5 standards across all production years.
One documented concern is premature failure of the camshaft phaser solenoids due to oil contamination, highlighted in Vauxhall Service Information Bulletin SIB 10‑027. The solenoids’ fine internal passages clog with sludge from extended oil intervals, causing variable valve timing faults and rough running.
All production years (2009–2017) meet Euro 5 standards (VCA UK Type Approval #VCA/EMS/7432).
The Vauxhall Z28NET is a 2,792 cc V6 naturally aspirated petrol engine engineered for executive and performance applications (2009–2017). It combines sequential multi‑point fuel injection with DOHC variable valve timing to deliver smooth power delivery and refined drivability. Designed to meet Euro 5 emissions standards, it balances performance with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,792 cc | |
| Fuel type | Petrol | |
| Configuration | V6, DOHC, 24‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 86.0 mm × 80.0 mm | |
| Power output | 152 kW (207 PS) | |
| Torque | 266 Nm @ 3,200 rpm | |
| Fuel system | Bosch Motronic MPFI (sequential) | |
| Emissions standard | Euro 5 | |
| Compression ratio | 10.4:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain‑driven camshafts with variable valve timing | |
| Oil type | GM Dexos1 (SAE 5W‑30) | |
| Dry weight | 165 kg |
The V6 layout provides smooth power delivery but requires GM Dexos1 (5W‑30) oil changed every 15,000 km to prevent cam phaser solenoid clogging and chain wear. Extended oil intervals allow sludge buildup, restricting oil flow to variable valve timing components and triggering P0011/P0021 codes. Use only RON 95 petrol to maintain emissions compliance. Pre-2013 engines should have solenoids inspected per SIB 10‑027 if rough idle or timing faults occur.
Oil Specs: Requires GM Dexos1 (5W‑30) specification (Vauxhall SIB 02‑018). Supersedes ACEA A3/B4 requirements.
Emissions: Euro 5 certification applies to all Z28NET production (2009–2017) (VCA Type Approval #VCA/EMS/7432). No Euro 6 variants exist.
Power Ratings: Measured under ISO 1585 standards. Output consistent across all model applications (Vauxhall TIS Doc. INS‑ENG‑028).
Vauxhall Technical Information System (TIS): Docs INS‑ENG‑028, SIB 10‑027, SIB 02‑018
VCA Type Approval Database (VCA/EMS/7432)
ISO 1585: Road vehicles — Engine test code
The Vauxhall Z28NET was used across Vauxhall's Insignia A platform with longitudinal mounting and no external licensing. This engine received platform-specific adaptations—reinforced subframes in the Insignia Sports Tourer and revised engine mounts in the VXR—and from 2013 minor ECU updates improved cold-start emissions, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the left cylinder bank near the timing cover (Vauxhall TIS INS‑ENG‑028). The 7th VIN digit is 'Z' for Z28NET engines. All variants use a black cam cover with "V6" embossed. Critical differentiation from turbocharged Z28LET: Z28NET lacks turbocharger, intercooler, and high-flow injectors. Cam phaser solenoids are not interchangeable with earlier V6 designs due to updated oil gallery geometry (Vauxhall SIB 10‑027).
The Z28NET's primary reliability risk is camshaft phaser solenoid clogging due to oil sludge accumulation, with elevated incidence in vehicles with extended oil change intervals. Vauxhall internal data from 2014 indicated over 11% of engines required solenoid cleaning or replacement before 120,000 km, while UK DVSA MOT records show emissions-related failures in 8% of Insignia V6 petrols from this era. Infrequent oil changes and urban driving accelerate deposit formation, making oil quality and interval adherence critical.
Analysis derived from Vauxhall technical bulletins (2009–2017) and UK DVSA failure statistics (2015–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL Z-28-NET.
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
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
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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VCA Certification Portal
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