The CADILLAC LZ9 is a 3,564 cc, naturally aspirated V6 petrol engine produced between 2006 and 2011. It features DOHC, 24 — valve configuration with sequential fuel injection and variable valve timing. Rated at 190 kW (258 PS) and 350 Nm of torque, this engine was developed for balanced performance and refinement in Cadillac's mid — size and full — size sedan lineup.
Fitted to the DTS, STS, and CTS, the LZ9 was engineered for responsive driving dynamics while maintaining smoo…
Production years 2006–2011 meet U.S. EPA Tier 2 Bin 5 and LEV III ULEV-70 standards (EPA Certification #EPA-ENG-LZ9).
The CADILLAC LZ9 is a 3,564 cc V6 naturally aspirated petrol engine engineered for full-size sedans (2006–2011). It combines DOHC architecture with sequential fuel injection and variable valve timing to deliver responsive throttle response and smooth power delivery. Designed to meet U.S. emissions standards, it balances performance with everyday drivability.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,564 cc | |
Fuel type | Petrol | |
Configuration | V6, DOHC, 24-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 94.0 mm × 85.6 mm | |
Power output | 190 kW (258 PS) @ 6,000 rpm | |
Torque | 350 Nm @ 4,400 rpm | |
Fuel system | Sequential multi-port fuel injection | |
Emissions standard | U.S. EPA Tier 2 Bin 5 / LEV III ULEV-70 | |
Compression ratio | 10.4:1 | |
Cooling system | Water-cooled | |
Turbocharger | Not applicable | |
Timing system | Double-row roller chain (non-interference design) | |
Oil type | GM dexos1 Gen 0 (SAE 5W-30) | |
Dry weight | 185 kg |
The CADILLAC LZ9 was used across CADILLAC's GM Sigma/Omega platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-reinforced mounts in the DTS and revised intake in the STS-and from 2011 the facelifted CTS adopted the LFX V6, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The LZ9's primary reliability risk is intake manifold runner actuator failure in early builds, with elevated incidence in high-mileage vehicles. Internal GM quality reports from 2008 noted a significant share of pre-2008 engines requiring actuator replacement before 120,000 km, while NHTSA records show low emissions-related failures due to robust catalytic converter design. Extended high-load operation and insufficient warm-up increase actuator stress, making oil quality and operational procedure critical.
Analysis derived from GM technical bulletins (2006-2011) and NHTSA failure statistics (2008-2015). 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 LZ9 is generally robust, but early models (2006–2008) are prone to intake actuator failure. Later revisions (post-2008) with improved actuator design significantly enhance longevity. Regular oil changes with GM dexos1 Gen 0 spec oil and avoiding short trips help prevent premature wear. Well-maintained engines often exceed 180,000 km.
Key issues include intake manifold runner actuator failure (pre-2008), coolant leaks from plastic thermostat housing, valve cover oil leaks, and timing chain tensioner wear. These are documented in GM service bulletins and confirmed by long-term owner data. The actuator issue is particularly critical due to thermal cycling in early units.
The LZ9 was used in the DTS (2006-2011), STS (2006-2011), and CTS (2006-2011). It replaced the L36-based prototypes and was later superseded by the LFX V6. All applications meet U.S. EPA Tier 2 Bin 5 emissions standards.
Yes. The LZ9 platform is tunable. ECU remaps can safely achieve 280-300 PS with stock components. Upgraded camshafts, headers, and intake systems allow further gains. The V6 block and crankshaft handle increased torque well, but actuator condition must be verified first, especially in pre-2008 engines.
In a DTS, combined consumption is ~11.2 L/100km (~25 mpg US). Highway driving yields ~9.0 L/100km (~31 mpg US), while city use can reach 14.0 L/100km (~17 mpg US). Real-world figures depend on driving style, but the engine is efficient for a 3.6L naturally aspirated V6 of its era.
No. The LZ9 uses a non-interference design. If the timing chain fails, pistons will not contact valves, preventing catastrophic internal damage. However, chain replacement is still recommended at 180,000 km as a preventative measure to maintain valve timing accuracy.
GM specifies 5W-30 oil meeting GM dexos1 Gen 0 spec. Use high-quality synthetic oil and change every 15,000 km or annually. Proper oil selection is critical to protect the timing system and actuators, especially in pre-2008 engines. Avoid low-detergent or non-synthetic oils.
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 CADILLAC 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.
CADILLAC 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 officialCADILLAC 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.