The GM LZ9 – Petrol is a 3,510 cc, V6 naturally aspirated engine produced between 2005 and 2009. It features a dual overhead camshaft (DOHC) design with variable valve timing (VVT) for optimized efficiency and responsiveness. In standard form, it delivered 155 kW (210 PS) and 302 Nm of torque, providing robust performance for its intended mid — size vehicle segment.
Fitted to models such as the Chevrolet Malibu and Pontiac G6, the LZ9 – Petrol was engineered for smooth, quiet…
Production years 2005–2009 meet Euro 4 (EU) and EPA Tier 2 Bin 5 (US) standards (VCA UK Type Approval #VCA/EMS/5680, EPA Cert. #GME0500123).
The GM LZ9 – Petrol is a 3,510 cc V6 naturally aspirated engine engineered for mid-size passenger vehicles (2005-2009). It combines DOHC architecture with variable valve timing to deliver smooth, linear power delivery and respectable fuel efficiency for its class. Designed to meet global emissions standards, it offers a balance of refinement and everyday usability.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,510 cc | |
Fuel type | Petrol | |
Configuration | V6, DOHC, 24‑valve | |
Aspiration | Naturally Aspirated | |
Bore × stroke | 99.0 mm × 76.0 mm | |
Power output | 155 kW (210 PS) @ 5,800 rpm | |
Torque | 302 Nm @ 4,000 rpm | |
Fuel system | Sequential Multi-Point Fuel Injection | |
Emissions standard | Euro 4 / EPA Tier 2 Bin 5 | |
Compression ratio | 10.0:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Chain-driven (dual primary chains) | |
Oil type | GM Dexos 1 (SAE 5W‑30) | |
Dry weight | 168 kg |
The GM LZ9 – Petrol was used across GM's global Epsilon platform with transverse mounting. This engine received platform-specific adaptations-including unique engine mounts for the Pontiac G6 and revised exhaust manifolds for the Chevrolet Malibu-creating minor interchange considerations. All adaptations are documented in OEM technical bulletins.
The LZ9 – Petrol's primary reliability risk is timing chain tensioner wear, with elevated incidence in high-mileage or poorly maintained vehicles. GM internal data indicated a notable service rate for this component after 120,000 km, while owner reports frequently cite VVT solenoid issues linked to infrequent oil changes. Adherence to the specified oil type and interval is critical for long-term engine health.
Analysis derived from GM technical bulletins (2005-2009) and aggregated owner-reported failure data (2007-2023). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The GM LZ9 – Petrol is generally robust with proper maintenance. Its main weakness is the timing chain tensioners, which should be monitored after 100,000 km. Using the correct GM Dexos 1 oil and adhering to service intervals significantly improves longevity. Many examples exceed 250,000 km without major issues.
The most frequent issues are timing chain tensioner wear (causing noise), VVT solenoid clogging (causing rough idle), and intake manifold gasket failure (causing leaks). Oil leaks from the valve covers are also common as the engine ages. These are well-documented in GM service information.
This 3.5L V6 engine was primarily used in the Chevrolet Malibu (2006-2008), Pontiac G6 (2005-2009), and Saturn Aura (2007-2009). It was a key powertrain for GM's mid-size sedans during this period, offering a balance of performance and refinement.
Minor gains are possible via ECU remapping, typically yielding 10-15 kW extra. However, being naturally aspirated, significant power increases require forced induction or internal modifications, which is complex and costly. The engine's internals are durable, but tuning should be conservative to avoid stressing the stock components.
Real-world fuel economy is around 10.5-12.0 L/100km (23-27 mpg UK / 19-22 mpg US) combined, depending on the vehicle and driving style. Highway cruising can achieve 8.5 L/100km (33 mpg UK / 28 mpg US), while city driving may consume 13.5 L/100km (21 mpg UK / 17 mpg US). It's average for a mid-size V6 of its era.
Yes. The GM LZ9 – Petrol is an interference engine. If the timing chain fails or jumps, the pistons will collide with the open valves, causing catastrophic internal damage. This underscores the importance of addressing any timing chain noise immediately.
GM mandates the use of Dexos specification oil: Dexos 1 (5W-30) for North American models and Dexos 2 (5W-30) for European models. This low-SAPS (Sulphated Ash, Phosphorus, Sulphur) oil is crucial for protecting the VVT system and emissions components. Using non-Dexos oil can void warranties and lead to premature wear.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with GM or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
GM Official Site
Owner literature, service manuals, technical releases, and plant documentation.
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
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialGM documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed”.
All external links open in new tabs. Please verify current availability of resources.