The CADILLAC LGX is a 3,564 cc, V6 naturally aspirated petrol engine produced between 2016 and 2023. It features DOHC, 24-valve configuration and General Motors' High Feature V6 architecture, delivering 235 kW (320 PS) and 367 Nm of torque. Its compact design and aluminum block construction provide smooth power delivery and weight efficiency in luxury applications.
Fitted to the CT6 and XT6, the LGX was engineered for refined cruising and balanced performance in Cadillac's flagship and mid-size luxury sedan and SUV applications. Emissions compliance was achieved through exhaust gas recirculation (EGR) and a three-way catalytic converter, enabling OBD-II and Euro 6 compliance across all production years.
One documented concern is intake manifold carbon buildup, particularly on units produced before 2019, due to oil vapor accumulation from the crankcase ventilation system. This issue, highlighted in General Motors Service Information Bulletin 06 03 02, led to airflow restriction and reduced performance. In 2019, GM introduced an upgraded crankcase ventilation (CCV) system with improved oil separation to reduce deposit formation.
Cadillac
All production years 2016–2023 meet OBD-II and Euro 6 emissions standards (VCA UK Type Approval #VCA/EMS/6781).
The CADILLAC LGX is a 3,564 cc V6 naturally aspirated petrol engine engineered for mid-size and full-size luxury applications (2016–2023). It combines aluminum construction with dual overhead camshafts to deliver smooth power delivery and quiet operation. Designed to meet OBD-II and Euro 6 standards, it balances refinement with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,564 cc | |
| Fuel type | Petrol | |
| Configuration | V6, DOHC, 24-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 94.0 mm × 85.0 mm | |
| Power output | 235 kW (320 PS) @ 6,800 rpm | |
| Torque | 367 Nm @ 4,500 rpm | |
| Fuel system | Bosch direct injection (up to 150 bar) | |
| Emissions standard | OBD-II, Euro 6 | |
| Compression ratio | 11.3:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Double-row timing chain | |
| Oil type | GM dexos1 Gen 2 (SAE 5W-30) | |
| Dry weight | 189 kg |
The DOHC V6 design provides smooth power delivery ideal for relaxed driving but requires adherence to 15,000 km oil change intervals to maintain chain longevity and lifter function. GM dexos1 Gen 2 (5W-30) oil is critical due to its formulation supporting hydraulic lifters and timing chain lubrication. Pre-2019 models should have the CCV system upgrade per GM SIB 06 03 02 if experiencing airflow restriction. Cooling system maintenance is essential to prevent overheating during sustained highway use. Engines used in high-mileage applications require valve train inspection every 100,000 km.
Oil Specs: Requires GM dexos1 Gen 2 (5W-30) specification (GM SIB 11 04 11). Supersedes ACEA A5/B5 requirements.
Emissions: OBD-II and Euro 6 certification applies to all production years (2016–2023) (VCA Type Approval #VCA/EMS/6781).
Power Ratings: Measured under SAE J1349 standards. Output consistent across fuel qualities meeting ASTM D4814.
General Motors Technical Information System (TIS): Docs A31000, A31030, SIB 06 03 02
VCA Type Approval Database (VCA/EMS/6781)
SAE International: J1349 Engine Power Certification Standards
The CADILLAC LGX was used across CADILLAC's CT6 and XT6 platforms with longitudinal mounting. This engine received platform-specific adaptations-integrated oil cooler in the CT6-V and revised intake manifolds in the XT6-and from 2023 the CT6 LCI adopted the LGX-T variant with updated engine management, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the cylinder block near the timing cover (GM TIS A31090). The 8th VIN digit indicates engine family ('L' for LGX series). All LGX units have black valve covers with "3.6L" and "High Feature" branding. Critical differentiation from LGX-T: Original LGX is naturally aspirated with Motronic ECU, while LGX-T features twin-turbocharging and drive-by-wire throttle. Service parts require production date verification - CCV systems before 06/2019 are prone to carbon buildup and should be replaced with post-revision units per GM SIB 06 03 02.
The LGX's primary reliability risk is intake manifold carbon buildup on pre-2019 builds, with elevated incidence in mixed driving conditions. Internal GM reports from 2018 indicated a significant number of pre-upgrade engines requiring intake cleaning before 120,000 km, while UK DVSA records show drivability-related failures were common in neglected examples. Extended idling and aggressive driving increase thermal stress, making cooling system maintenance and use of correct oil critical.
Analysis derived from GM technical bulletins (2016–2023) and UK DVSA failure statistics (2024–2025). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about CADILLAC LGX.
Comprehensive technical documentation and regulatory references
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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.
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