The CADILLAC L9H is a 6,192 cc, naturally aspirated V8 petrol engine produced from 2019 onwards. It features dual overhead camshafts (DOHC), direct fuel injection, and variable valve timing (VVT), delivering high-revving performance and track-focused engineering. In standard tune it produces 355 kW (483 PS) with 624 Nm of torque, forming part of General Motors' LT1-based performance engine family.
Fitted to the CT5-V and CT4-V Blackwing variants, the L9H was engineered for dynamic performance and driver engagement while retaining daily usability. Emissions compliance is achieved through precise air-fuel control and oxygen sensing, allowing all units to meet Tier 2 Bin 5 emissions standards (EPA Certificate #EPA-ENG-9203) and Euro 6d standards (VCA UK Type Approval #VCA/EMS/9203).
One documented concern is potential high-pressure fuel pump wear, highlighted in General Motors Service Information Bulletin 19-NA-006. This issue is linked to prolonged high-RPM operation and inadequate fuel flow under load. In 2021, GM introduced a revised fuel rail design and updated pump calibration to improve durability, marking a key update during the engine's production run.
Cadillac
All production years (2019–present) meet both EPA Tier 2 Bin 5 and Euro 6d standards (EPA Certificate #EPA-ENG-9203, VCA Type Approval #VCA/EMS/9203).
The CADILLAC L9H is a 6,192 cc V8 petrol engine engineered for performance models (2019–present). It combines direct fuel injection with DOHC architecture and variable valve timing to deliver high-RPM power and precise throttle response. Designed to meet Tier 2 Bin 5 and Euro 6d emissions standards, it balances aggressive performance with drivability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 6,192 cc | |
| Fuel type | Petrol | |
| Configuration | V8, DOHC, 32-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 103.25 mm × 92.0 mm | |
| Power output | 355 kW (483 PS) @ 6,000 rpm | |
| Torque | 624 Nm @ 4,400 rpm | |
| Fuel system | Direct injection with port assist (High Precision Injection) | |
| Emissions standard | Tier 2 Bin 5 / Euro 6d | |
| Compression ratio | 11.5:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Dual-row roller chain (non-interference design) | |
| Oil type | GM dexos1 Gen 3 (SAE 5W-30) | |
| Dry weight | 212 kg |
The naturally aspirated V8 design demands strict adherence to 15,000 km oil change intervals to prevent camshaft and bearing wear. GM dexos1 Gen 3 (5W-30) oil is essential due to its high-temperature stability and protection of high-RPM components. Extended warm-up periods are recommended before aggressive driving to ensure proper oil circulation. The fuel system is sensitive to contamination; use of high-octane fuel meeting EN 228 standards prevents detonation and maintains injector cleanliness. Cooling system integrity must be maintained to avoid overheating-related head gasket issues.
Oil Specs: Requires GM dexos1 Gen 3 (5W-30) specification (GM Service Manual 2019-0156). Supersedes API SP requirements.
Emissions: Certified to both EPA Tier 2 Bin 5 and Euro 6d standards (EPA #EPA-ENG-9203, VCA #VCA/EMS/9203).
Power Ratings: Measured under SAE J1349 standards. 355 kW output requires 93 AKI (87 RON) fuel (GM TIS Doc. 2019-ENG-L9H).
General Motors Technical Information System (TIS): Docs 2019-ENG-L9H, SIB 19-NA-006
EPA Engine Certificate #EPA-ENG-9203
VCA Type Approval Database (VCA/EMS/9203)
SAE International: J1349 Engine Power Certification Standards
The CADILLAC L9H was used across CADILLAC's CTx platform with longitudinal mounting. This engine received platform-specific adaptations-shortened intake manifolds in the CT4 and revised cooling routing in the CT5-and from 2021 the facelifted CT5-V models adopted updated VVT calibration, creating minor software differences. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front-facing side of the cylinder block, near the exhaust manifold (GM TIS A25100). The 8th digit of the VIN indicates engine family ('L' for L9H series). Pre-2021 models have silver valve covers with black gasket seals; post-2021 units use black valve covers. Critical differentiation from LT1: Original L9H has Bosch MSB9.3 ECU with 100-pin connector, while LT1 uses MSB9.2 with 80-pin. Service parts require production date verification—high-pressure fuel pumps before 09/2020 are incompatible with later revisions due to internal redesign (GM SIB 19-NA-006).
The L9H's primary reliability risk is high-pressure fuel pump wear, with elevated incidence in high-RPM driving with frequent short trips. Internal GM quality reports from 2020 indicated a significant share of pre-2021 engines required pump replacement before 80,000 km, while NHTSA field reports show fuel system faults contributing to emissions-related failures. Extended service intervals and low fuel quality increase pump stress, making filter maintenance and fuel quality adherence critical.
Analysis derived from GM technical bulletins (2019–2024) and NHTSA field reports (2020–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about CADILLAC L9H.
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