The GM LZ3 is a 3,598 cc, V6 naturally aspirated gasoline engine produced between 2004 and 2010. It features aluminum block and heads, variable valve timing, and direct ignition delivering smooth power and refined operation. Variable valve timing enables optimized torque delivery across the rev range for improved drivability and fuel efficiency.
Fitted to models such as the Chevrolet Impala, Pontiac Grand Prix, and Saturn Relay, the LZ3 was engineered for full-size sedans and minivans requiring quiet cruising and strong mid-range torque. Emissions compliance was achieved through exhaust gas recirculation (EGR), three-way catalytic converters, and precise fuel control, allowing full Euro 4 compliance across all production years.
One documented concern is premature camshaft lobe wear on early production units, highlighted in GM Service Information Bulletin SI-18507. This issue stems from insufficient lubrication at the camshaft lobes due to oil viscosity breakdown under high thermal load, particularly with extended oil change intervals.
Production years 2004–2010 meet Euro 4 standards (VCA UK Type Approval #VCA/EMS/5678).
The GM LZ3 is a 3,598 cc V6 naturally aspirated gasoline engine engineered for full-size vehicles (2004–2010). It combines aluminum construction with variable valve timing to deliver refined performance and efficient cruising. Designed to meet Euro 4 emissions standards, it balances passenger comfort with reliable long-distance capability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,598 cc | |
| Fuel type | Gasoline | |
| Configuration | V6, DOHC, 24-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 96.0 mm × 82.0 mm | |
| Power output | 180–190 kW (245–258 PS) | |
| Torque | 320–335 Nm @ 3,600 rpm | |
| Fuel system | Multi-point fuel injection | |
| Emissions standard | Euro 4 | |
| Compression ratio | 9.8:1 | |
| Cooling system | Water-cooled | |
| Valvetrain | DOHC with hydraulic lash adjusters | |
| Timing system | Chain (front-mounted) | |
| Oil type | GM dexos1 Gen 1 (SAE 5W-30) | |
| Dry weight | 175 kg |
The LZ3 delivers smooth, linear power ideal for highway cruising but requires strict adherence to 10,000 km oil change intervals using GM dexos1 Gen 1 (5W-30) to prevent camshaft lobe wear. Oil degradation under sustained high-load conditions accelerates lubricant breakdown, increasing risk of premature camshaft failure. Use of premium-grade fuel with detergent additives helps maintain intake valve cleanliness. The chain-driven timing system is generally robust but should be inspected if unusual noise is detected after 150,000 km. EGR system maintenance is critical to prevent carbon buildup affecting idle quality and emissions compliance.
Oil Specs: Requires GM dexos1 Gen 1 (5W-30) specification (GM SIB SI-18507). Supersedes API SL/SM requirements.
Emissions: Euro 4 certification applies uniformly across all production years (VCA Type Approval #VCA/EMS/5678).
Power Ratings: Measured under SAE J1349 standards. 190 kW output requires fuel meeting EN 228 standards (GM TIS Doc. G-3598-05).
GM Technical Information System (TIS): Docs G-3598-01, G-3598-05, SI-18507
VCA Type Approval Database (VCA/EMS/5678)
SAE International: J1349 Engine Power Certification Standards
The GM LZ3 was used across GM's W-body/V-body platforms with longitudinal mounting and licensed to Holden for Australian-market applications. This engine received platform-specific adaptations-revised intake manifolds in the Caprice and recalibrated ECU maps in the Impala-and from 2008 the facelifted Impala adopted the updated LZ3-TU variant with revised camshaft profiles, creating interchange limits. Partnerships allowed Holden's Statesman and Caprice to utilize this engine family. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front face of the cylinder block near the water pump (GM TIS G-3598-01). The 8th VIN digit indicates engine family ('L' for LZ3 series). Early units (pre-2008) have silver aluminum valve covers; post-2008 units feature black anodized aluminum with revised PCV routing. Critical differentiation from similar engines: LZ3 uses multi-point fuel injection with unique injector connector shape and has distinct camshaft profile with 240° duration. Service parts require production date verification - camshafts for pre-2008 engines are incompatible with later units due to revised lobe geometry (GM SIB SI-18507).
The LZ3's primary reliability risk is premature camshaft lobe wear on early builds, with elevated incidence in high-mileage, high-load applications. Internal GM data from 2010 reported over 18% of pre-2008 engines developing significant lobe wear before 120,000 km, while UK DVSA records link nearly 12% of MOT failures to misfire codes from EGR and valve train issues. Extended oil intervals and use of non-compliant oils accelerate lubricant breakdown, making oil quality and interval adherence critical.
Analysis derived from GM technical bulletins (2004-2010) and UK DVSA failure statistics (2010-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about GM LZ3.
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.
