2010 Vortec 4.3L V-6 (LU3)
4.3L V-6 (LU3) TRUCK ENGINE
• Oil Cooler system for Chevrolet Express and GMC Savana
• GM LAN Capability with E37 ECM
• 58X Crankshaft Sensing And 4X Cam Sensing
• Direct Ignition System
• Electronic Throttle Control
• Second Knock Sensor
• Dual Close-coupled Catalytic Converters For Lower Emissions
• Water Pump with Improved Durability features
• Precision Cast Rocker Arms
• Teflon Front Crankshaft Seal For Durability
• Aluminum Front Cover And Gasket
• Oil Pan with Noise Suppression and Improved Gasket Sealing features
• Threaded Block Heater Hole
• Low Permeability Intake System Sealing
• Three-layer Exhaust Heat Shields Reduce Noise
• Oil Pump Stub Shaft
• Regulated Voltage Control For Cooling Fan
• Extended Life Spark Plugs
• Lead Free Crank Thrust Bearing And Balance Shaft Bushings
• Extended Life Coolant
• GF4 Engine Oil Extends Durability
• Advanced Rate-Based Diagnostics
2010 Vehicle applications
The Vortec 4.3L V6 (LU3) is available in the Chevrolet Silverado and Express and the GMC Sierra and Savana for 2010, and is mated with the Hydra-Matic 4L60 (M30) four-speed automatic transmission.
Carryover Features and Benefits from 2009 model year
OIL COOLER SYSTEM
New oil cooler standard for GMC Savana and Chevrolet Express. The cooler will be mounted in the radiator end tank, and the lines will connect up to an oil cooler adapter mounted between the block and the oil filter. Purpose is to ensure appropriate oil temperatures under load (GVW and GCW), for all vehicle operating conditions.
GM LAN CAPABILITY WITH E37 ECM
The E37 controller allows the 4.3L V-6 to communicate with the Local Area Network electrical architecture on the Chevrolet Silverado and GMC Sierra, and the Chevrolet Express and GMC Savana for 2009. It also enables the 4.3L V-6 to communicate with the T42 transmission controller in the four-speed automatic transmission.
58X CRANKSHAFT SENSING AND 4X CAM SENSING
More precise ignition control is made possible with a new crankshaft sensing reluctor wheel, similar to the Gen IV V-8 engines, which enables the crankshaft position to be sensed 58 times per revolution. In addition, valve timing is now sensed with the addition of a sensor wheel to the camshaft.
DIRECT IGNITION SYSTEM
The ignition system is now fired electronically, and uses three coils, each of which fires two cylinders. The coils are mounted above the former distributor location. A shorter oil-pump driveshaft was necessary to replace the former distributor shaft-driven oil pump.
ELECTRONIC THROTTLE CONTROL
An electric motor on the intake throttle takes command from the engine control module and then opens and closes the throttle plate. The accelerator pedal is connected to a sensor that provides the ECM with driver input. The system allows multiple throttle progressions or algorithms, which operate the throttle at varying rates according to operating conditions and driver demands. It also has built-in default settings that protect the engine and ensure safe operation in the event of malfunction with the ETC or other engine subsystems.
SECOND KNOCK SENSOR
A second knock sensor is present to improve spark control, which enhances more complete combustion and improves engine efficiency.
WATER PUMP WITH IMPROVED DURABILITY FEATURES
A machined water pump combined with a specific gasket allows for better sealing of the pump to the block, and lessens the possibility of coolant leakage.
LEAD FREE CRANK THRUST BEARING AND BALANCE SHAFT BUSHINGS
The thrust bearing for the crankshaft, which handles longitudinal loads, is featured on all 4.3L V6 applications. In addition, the bushings which carry the balance shaft have also been modified to eliminate lead.
DUAL CLOSE-COUPLED CATALYTIC CONVERTERS FOR EXHAUST
The converter system is primarily designed to lower emissions. It features two close-coupled converters, which are located closer to the exhaust manifold to enhance their effectiveness. Converters closer to the exhaust manifold reach operating temperatures quickly and reduce start-up emissions.
PRECISION CAST ROCKER ARMS REPLACE STAMPED STEEL
The increased volume in which precision cast rocker arms are used by GM engines enables the replacement of the former stamped steel rocker arms, which can have larger variances in dimensions.
TEFLON FRONT CRANKSHAFT SEAL FOR DURABILITY
Long-term durability is enhanced with a special Teflon front crankshaft seal.
ALUMINUM FRONT COVER AND GASKET
To fit the crankshaft sensor reluctor wheel, a larger aluminum front engine cover replaces the former plastic component. The aluminum cover is also designed to reduce engine noise. The engine block was modified to accept the front cover.
OIL PAN WITH NOISE SUPRESSION
The aluminum oil pan, which fastens to the engine block and transmission bell housing to enhance powertrain rigidity, gets additional ribbing that makes it stiffer and adds to its ability to suppress engine noise. The pan also uses a gasket that aids its long-term ability to remain sealed to the engine block.
THREADED BLOCK HEATER HOLE
The block heater hole is threaded, which will improve the long-term durability of the sealing of the block heater plug and the block.
LOW PERMEABILITY INTAKE SYSTEM SEALING
To ensure minimal emissions from the fuel mixture seeping out of the intake system, the seals for the entire system feature a low-permeability compound.
THREE-LAYER EXHAUST HEAT SHIELDS REDUCE NOISE
The exhaust manifold features three layers of insulated tubing to reduce exhaust noise.
OIL PUMP STUB SHAFT
The former distributor was replaced by a bracket with three ignition coils, and underneath this bracket the distributor drive is replaced by a stub shaft which drives only the oil pump.
REGULATED VOLTAGE CONTROL FOR COOLING FAN
The electrically operated cooling fan is controlled by the temperature of the engine, and only operates when the engine requires further cooling of the coolant. This control keeps the engine at its optimal operating temperature, and improves efficiency when the fan is not required.
EXTENDED LIFE SPARK PLUGS
The platinum-tipped spark plugs extend anticipated plug life to 100,000 miles to keep maintenance at a minimum.
EXTENDED LIFE COOLANT
DEXCOOL coolant maintains its cooling and corrosion-inhibiting properties for 150,000 miles.
GF-4 ENGINE OIL EXTENDS DURABILITY
GF-4 engine oil reduces deposits, extends oil change intervals, improves fuel economy and extends the life of emissions control systems.
ADVANCED RATE-BASED DIAGNOSTICS
Rate-based diagnostics monitoring protocol are used to improve the robustness of the Onboard Diagnostics System (OBD II) and ensure optimal emissions control performance.
LOW MAINTENANCE
The platinum spark plugs have a recommended service life of 100,000 miles, while the DEXCOOL coolant is expected to remain effective for 150,000 miles.
OVERVIEW
The Vortec 4.3L V-6’s excellent torque, fuel efficiency, durability, low cost of ownership and steady improvement all contribute to its popularity as a base engine in light-duty applications. It powers more trucks around the globe than just about any V-6 engine in current production. The Vortec 4.3L V-6 is the base engine for entry level full-size Chevrolet Silverado and GMC Sierra pickups and full-size Chevrolet Express and GMC Savana vans.
This 90-degree V-6 was developed in the mid-1980s by removing two cylinders from GM’s legendary small block V-8. A counter-rotating balance shaft was employed to balance primary crank vibration. The low-end torque delivery of an overhead-valve engine, combined with continued improvements in noise, vibration and harshness control and the latest electronic controls have kept the Vortec 4.3L in high demand.
The Vortec 4.3L was upgraded midway through 2006 with cracked powder-metal connecting rods for more precise rod bearing clearance. The connecting rod is connected to the piston at one end and to the crankshaft at the other end. During its processing, the rod is hot forged, sintered in a furnace, machined and then the cap is fractured from the rod portion. This fracture joint is used to accurately position the cap to the rod during engine assembly.
The Vortec 4.3L continues to remain a workhorse for entry-level truck customers, while setting a standard in marine and industrial applications around the globe. It is popularly used in fork lift trucks, for example, and as an uplevel engine in the marine industry. As a classic V-6, it delivers outstanding torque and good specific output in an economical, high-value package, while continuing to surpass increasingly stringent government emissions standards.
The Vortec 4.3L V-6 is produced in Romulus, Michigan.