GM 4.3L LV3 Ecotec: Everything You Need To Know

Silverado has had an incredible history of success with its EcoTec3 V-6 engine. The new all-aluminum design was first introduced in 2014.

Still, it builds on nearly 60 years worth of experience, which Chevy small block engines have undergone under some harsh conditions, including job sites and race tracks around the world.

This fifth generation of these legendary engines incorporates advanced technologies such as race-proven aluminum engine blocks for long life; six-bolt main caps with cross bolts, which make them quieter and smoother operation when compared to earlier models.

Oil jet-cooled pistons ensure more consistent power under high heat conditions in both racing or streetcars alike!

What are GM 4.3L Ecotec Engines? 

On the tail-end of the year 2012, GM announced the release of the new engine, the GM 4.3 Lv3.

The GM 4.3 Ecotec3 engine or sometimes described as GM 4.3, LV3 Ecotec, is a naturally-aspirated gasoline engine debuted in the 2013 Chevrolet Silverado and GMC Sierra as their base engine option.

This is the engine designed by General Motors to use in pickup trucks. 

It is part of GM’s fifth generation of a small-block engine named after EcoTec3 in pickup trucks, replacing the fourth generation small block engines known as the Vortec engines.

The EcoTec engine lineup consists of the 5.3 V8 L86, 6.2 V8 L86, and this engine. 

The GM 4.3 engine is based on its predecessor; it was built around V8’s small block with a two-cylinder removed. On top of that, it also features modern technologies like direct fuel injection, cylinder deactivation, continuously variable valve timing, piston cooling jets, active fuel management, and aluminum cylinder heads and block. 

The engine’s power output is rated at 285 HP at 5,300 RPM and 330 lb-ft of torque at 3,900 RPM. The emissions are controlled by a close-coupled catalytic converter, return-less fuel rail, Quick sync 58X ignition, and a fast-response oxygen sensor. 

Engine Specifications and Design:

  • Production Run: 2013 – Present
  • Cylinder Head Material: Aluminum
  • Cylinder Block Material: Aluminum
  • Configuration: V6
  • Bore: 99.6 mm
  • Stroke: 92.0 mm
  • Valvetrain: OHV two valves per cylinder
  • Displacement: 4.3 L (4301 cc)
  • Compression Ratio: 11.0
  • Weight: 380 lbs. 
  • Maximum HP: 297 HP at 5,300 RPM
  • Maximum Torque: 330 lb-ft at 3,900 RPM

Engine Design:

Let’s take a look inside the engine!

Cylinder Block

The GM 4.3 EcoTec engine shares some design elements with GM’s original small-block V8, including a 90-degree cylinder angle and 4,400-inch bore centers. The engine’s bore and stroke dimensions are 99.6 mm and 92 mm, respectively.

Compared to the fourth-generation engine, the fifth-generation engine has a new aluminum cylinder block. 

The block is modified and refined to cater to the engine-driven fuel pump and vacuum pump mounting. It also employs new engine mount attachments, improved sealing, oil-spray piston cooling, and new knock sensor locations.  

Cylinder Head

The design of the GM 4.3 Ecotec cylinder head was built on the foundation of high-performance, race-proven airflow characteristics of the previous small-block heads and matches it with a new direct-injection combustion system.

As we mentioned, the airflow is greatly improved, especially in the higher range of RPM. This is good for a wider horsepower band as well as low-rpm torque. 

Compared to the fourth-generation cylinder head design, the fifth-generation head features a smaller combustion chamber designed to complement the volume of the piston dish.

The dished pistons, alongside smaller combustion chamber sizes, mate to get an 11.0 compression rating. 

The spark plug angle and placements have been modified to move farther into the chamber. This puts the electrode closer to the center of the combustion chamber, supporting the direct injection system.

Further, the engine features large, rectangular, and straight intake ports that feature a slight twist to have a better mixture movement, complemented by a reversal of the intake and exhaust valve positions compared to the fourth generation design. 

New valve locations for the new exhaust port shapes, with new port opening locations at the manifold face. The valvetrain components include roller-pivot rocker arms and durable valve springs.

Oiling System

The oiling system of the GM 4.3 Ecotec engine is revised and features a new dual pressure control and variable displacement vane pump. This allowed the increase in the flow capacity.

To add, the engine also has an oil-spray piston cooling – all of the fifth-generation engines have this. 

There are eight oil squirters in the engine block spray the underside of each piston and the surrounding cylinder wall with friction-reducing oil for an added layer of cooling.

The significance of oil spraying is important in maintaining the optimal temperature of the engine, promoting a safer environment for long-term durability. 

Dual-Equal Cam Phasing

All the fifth-generation engines feature a dual-equal camshaft phasing or variable valve timing that works with the Active Fuel Management to improve the fuel economy, maximizing engine performance in different conditions.

Installed on the front of the camshaft is a vane-type phaser to change the angular orientation, adjusting the timing of valve operation on the fly. 

The dual-equal cam phasing system adjusts the camshaft timing at the same rate for the intake and exhaust valves. The system also allows a single stream of torque delivery with near-peak levels over a wide RPM range.

It is also a great tool for controlling exhaust emissions. The phaser is actuated by hydraulic pressure and flow from engine oil, managed by a solenoid. 

Direct Injection

The direct injection system is across the board for all fifth-generation GM engines. In this type of fuel feeding, the fuel is placed closer to where it will ignite, enabling a greater combustion efficiency.

It also allows a far better burn in the air-fuel mixture and operates at a lower temperature than the usual port injection. 

High-Pressure Fuel Pump

The 4.3 Ecotec engine operates on a direct injection system; all fifth generations engines are. Therefore, it needs a high-pressure pump that can provide such demands for its engine.

The engine needed a very high-pressure pump in addition to the conventional fuel tank-mounted pump. A demanding number of 22,000 psi is needed for this. 

The pump is placed in the valley between the cylinder heads, driven by the camshaft at the rear of the engine. GM added a soft stop control strategy for the pump’s internal solenoid that reduced the ticking sound of direct injection systems. 

Expanded Active Fuel Management Operation

This technology expands the range of operation of the engine by more than ten percent than the previous fourth-generation engine. This mechanism deactivates two cylinders under light load conditions – operating as a V4, and reactivates the cylinder when needed.

When the two cylinders are deactivated, the engine’s effort is lessened, consuming less fuel. The transition period happens less than two milliseconds. The newly added dual-mode oil pimp enables the fifth-generation engines such as the GM 4.3 Ecotec to engage the AFM earlier than fourth-generation applications. 

Applications of the GM 4.3 Ecotec Engine:

  • 2012 – 2021 Chevrolet Silverado 1500
  • 2014 – 2021 GMC Sierra 1500 
  • 2018 – Present Chevrolet Express 
  • 2018 – Present GMC Savanna 

Engine Tuning, Modifications, and Upgrades

An engine was made, which is also similar to the GM 4.3 Ecotec engine. The engine was called the 4.3 EcoTec3 Lv1 engine. The LV1 engine is a 4.3 Liter V6 engine produced by the same automaker.

It does not have that much difference from the LV3, but the most evident difference is that the LV1 engine does not have an Active Fuel Management technology or cylinder deactivation. 

This version was introduced on the 2018 GMC Savana and Chevrolet Express. The engine’s rating is 285 HP at 5,300 RPM and 3-5 lb-ft of torque at 4,000 RPM. 

Problems Surrounding GM 4.3 Ecotec Engine: 

Every engine that you know has its issues and problems that will come out sooner or later depending on the preventive care and maintenance of the owner. It is clear that the engine will deteriorate and somehow drop and need some part replacements because of age, mileage, and external factors.

The GM 4.3 Ecotec engine is no exception. 

1. Excessive Fuel Consumption

We will first mention the biggest problem in the 4.3 Ecotec engine, the excessive fuel consumption. This issue is the succeeding action of a weak Active Fuel Management technology development.

Though it is meant to save you from consuming a lot of fuel, it proves and shows to be otherwise. 

On top of that, some owners said that the Active Fuel Management lifters have not been very good too; and have a history of failing. Given the situation and clamor, GM was not able to identify what really caused the issue. 

2. Carbon Build-up

Carbon build-up is also a big problem for the GM 4.3 Ecotec engine. As we all know, direct-injection engines have the tendencies for a carbon build-up in the intake ports and valves.

However, the fuel cleans the surface inside from the blow-by motor oil and exhaust gases with the port fuel injection. 

Unfortunately, those benefits are not experienced in the direct-injection system. If the engine does not have the gasoline cleaning effect, there will come a time that a carbon build-up will occur.

Huge chunks of sludge will block the airflow that may restrict the engine’s performance potential, and have some drivability issues. 

The engine may show signs of carbon build-up around the 70,000 miles to 100,000 thousand range; it can be earlier or later. Some of the symptoms include unsteady acceleration, rough idling, sputtering at idle, and loss of power.

The way to fix this issue is walnut blasting. 


The GM 4.3 Ecotec engine with its technology and development deserves to be praised. Despite being a heavyweight V8 engine, the engine has the capacity to consume only the same as a V4 engine, reducing your fuel costs and other expenses.

This engine is best in different driving conditions and can fit in different driving styles. 

1 thought on “GM 4.3L LV3 Ecotec: Everything You Need To Know”

  1. will the lv1 or lv3 crankshaft fit into the 1999 and newer 4.3 engine blocks and what are the differences. thanks dave


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