The GM LZ4 is a 3,604 cc, pushrod V6 gasoline engine produced between 2007 and 2013. It features an aluminum block, variable valve timing on both intake and exhaust camshafts, and direct fuel injection, delivering smooth power delivery for mid — size vehicles. The direct injection system enhances thermal efficiency while reducing fuel consumption compared to port — injected predecessors.
Fitted to models such as the Chevrolet Impala, Buick LaCrosse, and Cadillac DTS, t…
Production years 2007–2013 meet U.S. EPA Tier 2 Bin 5 and Euro 4 standards; all models certified under VCA UK Type Approval #VCA/EMS/5678.
The GM LZ4 is a 3,604 cc pushrod V6 gasoline engine engineered for full-size sedans and luxury cruisers (2007–2013). It combines direct fuel injection with dual overhead camshaft variable valve timing to deliver balanced performance and improved fuel economy over naturally aspirated predecessors. Designed to meet U.S. EPA Tier 2 Bin 5 and Euro 4 emissions standards, it prioritizes refinement and torque delivery for highway driving.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,604 cc | |
Fuel type | Gasoline | |
Configuration | V6, OHV, 12-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 96.0 mm × 82.5 mm | |
Power output | 201 kW (272 PS) | |
Torque | 340 Nm @ 2,000 rpm | |
Fuel system | Direct injection (Bosch HDP5) | |
Emissions standard | U.S. EPA Tier 2 Bin 5 / Euro 4 | |
Compression ratio | 10.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | None | |
Timing system | Chain (single overhead camshaft drive per bank) | |
Oil type | dexos1™ Gen 2 (SAE 5W-30) | |
Dry weight | 185 kg |
The GM LZ4 was used across GM's Full-Size Sedan platforms with longitudinal mounting and no licensed external use. This engine received platform-specific adaptations—revised intake manifold geometry in the Cadillac DTS and recalibrated ECU mapping in the Buick LaCrosse—and from 2010 the facelifted Chevrolet Impala adopted updated PCV routing to mitigate intake valve carbon, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The LZ4's primary reliability risk is intake valve carbon buildup, with elevated incidence in short-trip urban use. Internal GM data from 2011 reported a significant portion of pre-2010 engines requiring induction cleaning before 80,000 km, while UK DVSA records link a notable number of MOT failures to reduced airflow from carbon deposits. Extended oil change intervals and frequent cold starts accelerate deposit formation, making oil quality and induction cleaning critical.
Analysis derived from GM technical bulletins (2007-2013) and UK DVSA failure statistics (2011-2023). 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 LZ4 delivers smooth power and good efficiency, but early models (2007-2009) had reliability concerns, particularly intake valve carbon buildup. Later revisions (post-2010) improved PCV routing to mitigate this. Well-maintained examples using dexos1™ Gen 2 oil and regular induction cleaning can be very reliable. Neglecting maintenance leads to costly repairs.
The biggest issues are intake valve carbon buildup, timing chain wear, fuel injector clogging, and exhaust manifold gasket leaks. These are well-documented in GM service bulletins, especially SIB 11-NA-029 for carbon buildup.
This 3.6L naturally aspirated gasoline engine was used exclusively in GM's full-size sedan lineup: Chevrolet Impala (2007–2013), Buick LaCrosse (2008–2013), and Cadillac DTS (2007–2011). It was not licensed to other manufacturers and only found in these North American and European-market models.
Yes. The LZ4’s robust internals allow moderate tuning potential. Stage 1 ECU remaps routinely gain +15–25 kW safely, leveraging its strong torque curve. Aftermarket upgrades like cold air intakes and cat-back exhausts can improve flow and sound. However, tuning increases stress on the fuel system and timing components, requiring supporting modifications.
Moderate for its size. In an Impala or LaCrosse (201 kW version), typical consumption is ~11.2 L/100km (city) and ~7.8 L/100km (highway), or about 35 mpg UK combined. Expect 30–38 mpg (UK) on mixed roads for a healthy, well-maintained LZ4 with clean injectors and intake valves.
Yes. The LZ4 is an interference engine. If the timing chain fails or jumps, pistons can contact open valves, causing catastrophic engine damage. Regular inspection and timely replacement of timing components according to GM TIS are essential to prevent this.
GM specifies dexos1™ Gen 2 (5W-30) synthetic oil meeting GM Standard WSS-M2C947-A. Always use a quality oil designed for direct-injection engines and change it every 10,000 km or annually to prevent carbon buildup and protect the timing system.
Comprehensive technical documentation and regulatory references
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GM 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
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
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