The CADILLAC L86 is a 6,162 cc, naturally aspirated V8 petrol engine produced between 2015 and 2020. It features OHV, 16-valve configuration with variable valve timing and direct fuel injection. Rated at 335 kW (455 PS) and 623 Nm of torque, this engine was developed for performance-oriented applications in Cadillac's full-size luxury and performance lineup.
Fitted to the CT6-V6 and high-trim CT6 models, the L86 was engineered to deliver strong low-end pulling power while maintaining refinement and smoothness. Emissions compliance was achieved through a close-coupled three-way catalytic converter 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 lifter wear, particularly in early production units before 2017. This issue, referenced in General Motors Service Information Bulletin 17-NA-021, is attributed to oil flow restriction in the lifter gallery during cold starts. In 2017, GM revised the oil gallery design, improving durability in later models.
Cadillac
Production years 2015–2020 meet U.S. EPA Tier 2 Bin 5 and LEV III ULEV-70 standards (EPA Certification #EPA-ENG-L86).
The CADILLAC L86 is a 6,162 cc V8 naturally aspirated petrol engine engineered for full-size luxury sedans (2015–2020). It combines OHV architecture with direct injection and variable valve timing to deliver strong low-RPM torque and smooth power delivery. Designed to meet U.S. emissions standards, it balances performance with everyday drivability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 6,162 cc | |
| Fuel type | Petrol | |
| Configuration | V8, OHV, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 103.3 mm × 92.0 mm | |
| Power output | 335 kW (455 PS) @ 5,750 rpm | |
| Torque | 623 Nm @ 4,400 rpm | |
| Fuel system | Bosch HDEV5 high-pressure direct injection (up to 2,000 bar) | |
| Emissions standard | U.S. EPA Tier 2 Bin 5 / LEV III ULEV-70 | |
| Compression ratio | 11.5:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Double-row roller chain (interference design) | |
| Oil type | GM dexos1 Gen 2 (SAE 5W-30) | |
| Dry weight | 220 kg |
The naturally aspirated V8 delivers strong low-RPM torque ideal for relaxed cruising and spirited driving but requires adherence to 15,000 km oil change intervals to prevent lifter and bearing wear. GM dexos1 Gen 2 (5W-30) oil is essential due to its shear stability and protection for the direct injection system. Extended idling or short-trip driving accelerates wear in pre-2017 engines with original-spec lifters. The Bosch HDEV5 fuel system is robust but sensitive to fuel quality; always use premium unleaded (RON 91+). Post-2017 models feature revised oil galleries per GM SIB 17-NA-021, significantly enhancing long-term reliability.
Oil Specs: Requires GM dexos1 Gen 2 specification (GM SIB 17-NA-021). API SP/ILSAC GF-6 compatible oils acceptable.
Emissions: EPA Tier 2 Bin 5 certification applies to all models (2015–2020) (EPA Type Approval #EPA-ENG-L86).
Power Ratings: Measured under SAE J1349 standards. Output consistent across fuel qualities (GM TIS Doc. C32100).
General Motors Technical Information System (TIS): Docs C32100, C32140, C32200, SIB 17-NA-021
EPA Engine Certification Database (EPA-ENG-L86)
SAE International: J1349 Engine Power Test Code
The CADILLAC L86 was used across CADILLAC's Omega platform with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-revised cooling routing in the CT6 and shorter accessory drives in the high-trim variants-and from 2019 the facelifted CT6 adopted the LF4 twin-turbo 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 C32200). The 8th VIN digit indicates engine family ('6' for L86 series). Pre-2017 models have silver valve covers with "L86" branding; post-2017 units use black valve covers with "L86" marking. Critical differentiation from LT1: L86 uses direct injection and OHV; LT1 uses similar architecture but different bore/stroke and calibration. Service parts require production date verification - lifters for engines before 08/2017 are incompatible with later units due to gallery redesign (GM SIB 17-NA-021).
The L86's primary reliability risk is lifter wear in early builds, with elevated incidence in high-mileage vehicles. Internal GM quality reports from 2017 noted a significant share of pre-2017 engines requiring lifter 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 lifter stress, making oil quality and operational procedure critical.
Analysis derived from GM technical bulletins (2015-2020) and NHTSA failure statistics (2017-2022). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about CADILLAC L86.
Comprehensive technical documentation and regulatory references
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EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
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