The CADILLAC LY7 is a 3,564 cc, naturally aspirated V6 petrol engine produced between 2005 and 2011. It features DOHC, 24-valve configuration with variable valve timing and sequential fuel injection. 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 STS, DTS, and CTS, the LY7 was engineered for responsive driving dynamics while maintaining smoothness and efficiency. Emissions compliance was achieved through close-coupled three-way catalytic converters and secondary air injection system, meeting U.S. EPA Tier 2 Bin 5 and LEV III ULEV-70 standards for its production run.
One documented reliability concern is premature intake manifold runner actuator failure, particularly in early production units before 2008. This issue, referenced in General Motors Service Information Bulletin 08-NA-016, is attributed to plastic gear degradation in the actuator motor. In 2008, GM revised the actuator design with reinforced gears, improving durability in later models.
Cadillac
Production years 2005–2011 meet U.S. EPA Tier 2 Bin 5 and LEV III ULEV-70 standards (EPA Certification #EPA-ENG-LY7).
The CADILLAC LY7 is a 3,564 cc V6 naturally aspirated petrol engine engineered for full-size sedans (2005–2011). 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 naturally aspirated V6 delivers responsive performance ideal for everyday driving but requires adherence to 15,000 km oil change intervals to prevent bearing and chain wear. GM dexos1 Gen 0 (5W-30) oil is essential due to its shear stability and protection for the timing chain system. Extended high-RPM operation or insufficient warm-up increases stress on the intake actuators in pre-2008 engines. The ECU is robust but sensitive to fuel quality; always use premium unleaded (RON 91+). Post-2008 models feature revised actuators per GM SIB 08-NA-016, significantly enhancing long-term reliability.
Oil Specs: Requires GM dexos1 Gen 0 specification (GM SIB 08-NA-016). API SM/ILSAC GF-4 compatible oils acceptable.
Emissions: EPA Tier 2 Bin 5 certification applies to all models (2005–2011) (EPA Type Approval #EPA-ENG-LY7).
Power Ratings: Measured under SAE J1349 standards. Output consistent across fuel qualities (GM TIS Doc. C37100).
General Motors Technical Information System (TIS): Docs C37100, C37140, C37200, SIB 08-NA-016
EPA Engine Certification Database (EPA-ENG-LY7)
SAE International: J1349 Engine Power Test Code
The CADILLAC LY7 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.
Locate the engine code stamped on the rear face of the cylinder block near the transmission bellhousing (GM TIS C37200). The 8th VIN digit indicates engine family ('7' for LY7 series). Pre-2008 models have silver valve covers with "LY7" branding; post-2008 units use black valve covers with "LY7" branding. Critical differentiation from LFX: LY7 uses sequential port injection; LFX uses direct injection. Service parts require production date verification - intake actuators for engines before 08/2008 are incompatible with later units due to gear redesign (GM SIB 08-NA-016).
The LY7'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 (2005-2011) and NHTSA failure statistics (2008-2015). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about CADILLAC LY7.
Comprehensive technical documentation and regulatory references
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CADILLAC 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.
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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
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