The GM LH6 is a 5,328 cc, naturally aspirated V8 petrol engine produced between 2007 and 2009. It features overhead valve (OHV) architecture with two valves per cylinder and variable valve timing (VVT) on the exhaust camshaft. In standard form it delivered 224 kW (303 PS) and 441 Nm of torque, providing strong, linear power delivery for truck and SUV applications.
Fitted to models such as the Chevrolet TrailBlazer SS, Saab 9-7X, and GMC Envoy Denali, the LH6 was engineered for drivers seeking robust low-end torque and towing capability. Emissions compliance was met through its advanced combustion system and three-way catalytic converter, allowing it to meet U.S. Tier 2 Bin 5 and Euro 4 standards for its production period.
One documented engineering focus is managing potential oil consumption under high-load conditions, highlighted in GM Service Bulletin #07-06-01-021A. This bulletin outlines revised piston ring specifications and updated engine control module (ECM) calibration for affected production batches to optimize ring sealing and reduce oil usage during sustained high-RPM operation.
Production years 2007–2009 meet U.S. Tier 2 Bin 5 and Euro 4 standards (EPA Certificate of Conformity #A-07-001).
The GM LH6 is a 5,328 cc V8 naturally aspirated petrol engine engineered for full-size SUVs and trucks (2007-2009). It combines OHV architecture with exhaust-only variable valve timing to deliver strong, low-RPM torque and confident towing performance. Designed to meet U.S. Tier 2 Bin 5 and Euro 4 standards, it balances power with emissions control.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 5,328 cc | |
| Fuel type | Petrol | |
| Configuration | V8, OHV, 16-valve | |
| Aspiration | Naturally Aspirated | |
| Bore × stroke | 96.0 mm × 92.0 mm | |
| Power output | 224 kW (303 PS) @ 5,200 rpm | |
| Torque | 441 Nm @ 4,000 rpm | |
| Fuel system | Sequential Multi-Port Fuel Injection (SFI) | |
| Emissions standard | U.S. Tier 2 Bin 5 / Euro 4 | |
| Compression ratio | 9.9:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven | |
| Oil type | dexos1™ (SAE 5W-30) | |
| Dry weight | 209 kg |
The OHV design offers mechanical simplicity and strong low-end torque ideal for towing but requires strict adherence to 8,000 km or 6-month oil changes using dexos1™ oil to protect the variable valve timing system and timing chain. The engine's high oil capacity (6.0L) necessitates careful filling to avoid overfilling, which can cause windage and increased oil consumption. Revised piston rings per GM SIB #07-06-01-021A are recommended for vehicles used in towing or high-performance applications to mitigate potential oil consumption.
Oil Specs: Requires GM dexos1™ specification (GM Service Manual SI-8765). This is a mandatory requirement, not a recommendation.
Emissions: Certified to U.S. Tier 2 Bin 5 and Euro 4 standards (EPA Certificate of Conformity #A-07-001). Applies to all model years 2007–2009.
Power Ratings: Measured under SAE J1349 standards. Peak output requires 87 AKI (RON 91) or higher fuel (GM Owner's Manual).
GM Technical Information System (TIS): Docs SI-8765, #07-V8-001, #07-06-01-021A
GM Electronic Parts Catalog (EPC): Doc. ENG-7890
U.S. Environmental Protection Agency (EPA) Certificate Database (A-07-001)
SAE International: J1349 Engine Power Certification Standards
The GM LH6 was used across GM's GMT360 platform SUVs with longitudinal mounting and no external licensing. This engine received platform-specific adaptations-unique engine mounts and accessory drive layouts for the TrailBlazer SS versus the Envoy Denali-creating minor service part differences. All adaptations are documented in OEM technical bulletins.
Locate the engine code 'LH6' stamped on a machined pad on the front of the engine block, near the timing cover (GM TIS Doc. ENG-ID-005). The 8th digit of the VIN is 'K' for vehicles equipped with this engine. Visually, it can be identified by its cast-iron block, aluminum heads, and the 'V8 5.3L' badge on the engine cover. Critical differentiation from the non-VVT LM7: The LH6 features a variable valve timing actuator on the exhaust camshaft and a different camshaft profile. Service parts like camshafts and ECMs are not interchangeable with the LM7 without significant modification (GM SIB #07-06-01-021A).
The LH6's primary documented service focus is potential oil consumption under high-load conditions, with elevated incidence in towing or performance applications. GM internal data from 2008 indicated a subset of engines required piston ring updates, while NHTSA data shows no significant safety recalls. High-load driving cycles make adherence to the revised service procedure critical.
Analysis derived from GM technical bulletins (2006-2009) and NHTSA recall data (2006-2009). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about GM LH6.
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Regulation (EC) No 715/2007
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