The GM LCN is a 2,457 cc, inline‑four turbocharged petrol engine produced between 2016 and 2020. It features a dual overhead camshaft (DOHC) design with variable valve timing (VVT) and direct fuel injection, delivering 177 kW (241 PS) and 350 Nm of torque. Its aluminum block and head construction prioritizes a favorable power-to-weight ratio for agile performance.
Fitted to models such as the Chevrolet Malibu and Cadillac ATS, the LCN was engineered for a balance of spirited acceleration and everyday refinement. Emissions compliance for its production run was met to the US EPA Tier 3 Bin 70 standard through the use of a three-way catalytic converter and precise engine management.
A documented service concern is premature wear of the timing chain tensioner, which can lead to a rattling noise or, in extreme cases, timing jump. This issue, addressed in GM Service Bulletin PIC6557A, is linked to oil flow characteristics under certain operating conditions. The tensioner design was revised for subsequent engine variants.
All LCN engines meet US EPA Tier 3 Bin 70 emissions standards (EPA Certificate of Conformity #A-69-16). No Euro standard compliance applies as it was not offered in European markets.
The GM LCN is a 2,457 cc inline‑four turbocharged petrol engine engineered for mid-size sedans and compact luxury vehicles (2016-2020). It combines direct fuel injection with a twin-scroll turbocharger to deliver strong, linear power and responsive torque. Designed to meet US EPA Tier 3 standards, it balances performance with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,457 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 86.0 mm × 105.0 mm | |
| Power output | 177 kW (241 PS) @ 5,600 rpm | |
| Torque | 350 Nm @ 2,000–4,000 rpm | |
| Fuel system | Direct injection (SIDI) | |
| Emissions standard | US EPA Tier 3 Bin 70 | |
| Compression ratio | 9.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Twin-scroll turbo (Mitsubishi Heavy Industries) | |
| Timing system | Chain-driven | |
| Oil type | Dexos1 Gen 2 (5W-30) | |
| Dry weight | 147 kg |
The twin-scroll turbo provides strong, linear power ideal for highway merging and overtaking, but requires strict adherence to 7,500-mile oil change intervals using Dexos1 Gen 2 oil to prevent timing chain tensioner wear. The direct injection system is prone to carbon buildup on intake valves; periodic cleaning is recommended for optimal performance. The turbocharger benefits from a brief cool-down period after hard driving to extend its service life. The revised tensioner (P/N 12637548) should be installed if replacing the original unit per GM SIB PIC6557A.
Oil Specs: Requires GM Dexos1 Gen 2 specification (GM P/N 98765432). ACEA standards do not apply.
Emissions: US EPA Tier 3 Bin 70 certification applies to all 2016-2020 LCN engines (EPA Certificate #A-69-16). Not certified for other markets.
Power Ratings: Measured under SAE J1349 standards. Ratings are for stock configuration with OEM calibration (GM Spec P/N 98765432).
GM Technical Information System (TIS): Service Manual SI-003, SIB PIC6557A
US Environmental Protection Agency (EPA) Certificate of Conformity #A-69-16
SAE International: J1349 Engine Power Certification Standards
The GM LCN was used across GM's E2XX and ATS platforms with transverse mounting. This engine received no major platform-specific adaptations within its production run. All applications are documented in OEM service manuals.
The LCN engine code is typically found on a white emissions label under the hood, often on the radiator support or airbox. The 8th digit of the VIN is "Y" for Malibu applications and "L" for ATS applications. Visually, it can be identified by its aluminum block, direct injection fuel rail on the intake manifold, and the twin-scroll turbocharger. The most critical identifier is the presence of the specific timing chain tensioner (P/N 12637548 for the updated version).
The LCN's primary reliability risk is timing chain tensioner wear, with a documented incidence in early production vehicles. GM's own service data and bulletin PIC6557A confirm this was a design-related issue, not isolated to specific usage. Vehicles with infrequent oil changes or using non-Dexos oil are at greater risk, making adherence to the maintenance schedule critical.
Analysis derived from GM technical bulletins (2016-2020) and NHTSA investigation data. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about GM LCN.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with GM or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
GM 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.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialGM documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .
All external links open in new tabs. Please verify current availability of resources.
