What year did Chevy start variable valve timing?

Chevrolet started using variable valve timing (VVT) in the 2006 model year on select Ecotec four-cylinder engines.

Variable valve timing helps engines optimize combustion by adjusting when intake and exhaust valves open and close. GM rolled VVT out across Chevrolet’s lineup gradually, beginning with smaller four-cylinders and expanding to larger V6 and turbocharged engines in subsequent years. This article traces the timeline and highlights notable engines and models that used VVT.

Timeline of Chevrolet's VVT adoption

The following milestones show how Chevy introduced VVT and expanded its use across engines and vehicles. Exact availability can vary by model year, trim, and market.

• 2006 model year: First adoption of VVT on a Chevrolet Ecotec four-cylinder engine in select models, marking Chevy’s initial entry into variable valve timing.


• Late 2000s: Expansion of VVT to larger GM V6 families (including 3.5L/3.6L variants) across several Chevy cars, trucks, and SUVs.


• 2010s: Widespread adoption across turbocharged four-cylinders and upscale V6 configurations, with continued refinements to VVT control and integration with direct injection and turbocharging.

These milestones reflect the general chronology of Chevrolet’s VVT rollout within GM’s broader powertrain strategy.

Notable engines and applications

Chevrolet deployed VVT across a range of engines in different generations, including the Ecotec 2.4L four-cylinder, various 3.6L V6 configurations, and turbocharged engines in models such as the Cruze, Malibu, Equinox, Camaro, and others. Availability depended on engine code, market, and model year.

2.4L Ecotec family

The 2.4L Ecotec four-cylinder was among the earliest Chevrolet engines to incorporate VVT, improving efficiency and throttle response in models that used this powerplant in the mid- to late-2000s.

3.6L V6 family

GM’s 3.6L V6 variants with VVT began appearing in Chevy SUVs, crossovers, and pickups as the technology matured, delivering both torque and efficiency benefits.

2.0L turbo and other modern engines

In the 2010s, additional Chevy engines—especially turbocharged four-cylinders and later direct-injected variants— adopted VVT as part of GM’s broader efficiency program.

Summary: Chevrolet began adopting variable valve timing in the mid-2000s, with the earliest VVT-enabled engines appearing around the 2006 model year on the 2.4L Ecotec family, and the technology gradually expanding to multiple powertrains across decades. This shift helped improve fuel economy, emissions, and performance across Chevrolet’s lineup.

What year did GM start using VVT?

In 2002, GM released its DOHC inline Six 4.2L engine, starting a new generation of engines with variable cam timing. Given the term cam phasing by Delphi, the company that developed and manufactures the system, the engine first appeared in S/T model SUVs such as the Chevy TrailBlazer.

What year did GM start cylinder deactivation?

GM first started cylinder deactivation with the Cadillac L62 "V8-6-4" engine in 1981, but it was only available for one year. The modern version, Active Fuel Management (AFM), was introduced in 2005 for small SUVs, followed by full-size trucks and SUVs in 2007. 

• 1981: Cadillac's L62 "V8-6-4" was the first production car with cylinder deactivation, but the system was unreliable and discontinued after one year, notes Wikipedia and GM Authority. 
• 2005: GM reintroduced the technology in modern vehicles with the Active Fuel Management (AFM) system, starting with small SUVs, according to V8buick.com and GM Authority. 
• 2007: AFM was expanded to include full-size trucks and SUVs, as seen on the 2007 GMT900 platform, and was featured in the 5.3L and 6.0L engines. 

What year to avoid Chevy Silverado 1500?

Years to avoid on the Chevy Silverado 1500 include 2014, 2015, and 2017, which are noted for electrical issues, transmission problems, and air conditioning failures. Other models to be cautious of are 2007-2011 due to engine issues like oil consumption from the AFM system, and 2019-2021 for lifter failures and engine bearing problems. 
This video discusses the worst and best years for Chevy Silverado trucks: 59sCar ExpertlyYouTube · Jun 4, 2025
Specific model years to avoid

• 2007–2011: The early versions of this generation (GMT900) are prone to the Active Fuel Management (AFM) system causing oil consumption, lifter noise, and potential engine damage. 
• 2012–2013: Owners reported significant issues with engines and transmissions, along with interior accessory malfunctions. 
• 2014: Considered one of the worst model years due to the highest number of recalls and complaints, especially regarding the new 8-speed transmission, electrical problems, and airbag failures. 
• 2015: Frequently cited as a model year to avoid due to transmission issues and electrical problems. 
• 2017: Had numerous complaints about a faulty transmission, leading to poor shifting and other malfunctions. 
• 2019–2021: The first few years of the T1XX generation saw a rise in problems like Dynamic Fuel Management (DFM) lifter failures and engine bearing issues, resulting in recalls. 

You can also watch this video to learn about the best and worst years for Chevy Silverado: 57sCar Lensy YouTube · Sep 11, 2025
Reasons for avoidance

• Engine Problems: Oil consumption, lifter failures, and other issues were common in the early AFM/DFM years (2007–2011, 2019–2021). 
• Transmission Issues: Rough shifting and failures were prevalent in the early third-generation trucks, particularly in 2014 and 2017. 
• Electrical and Air Conditioning Problems: Electrical systems, including the AC, were a frequent source of complaints in the 2014 model year, which also had airbag issues. 

How to tell if 5.3 has VVT?

You can tell if a 5.3L engine has VVT by looking for a camshaft phaser actuator on the front timing cover, which has a noticeable "bump". A non-VVT engine will have a flat timing cover in that area. Another key indicator is the electrical harness on the timing cover; VVT engines have a 5-pin connector for the VVT and camshaft sensors, while non-VVT engines will have a 3-pin connector for only the camshaft sensor.
 
This video shows how to identify if an LS engine has VVT by looking at the timing cover: 58sDinoco BlueYouTube · Oct 21, 2020
Key indicators

• Timing cover: VVT engines have a visible "bump" or protrusion on the timing cover for the camshaft phaser actuator. Non-VVT covers are flat in this area. If the engine is in the vehicle, you may need to look from underneath to see the cover clearly. 
• Electrical connector: VVT engines have a 5-pin electrical connector on the timing cover for the VVT and camshaft position sensors. Non-VVT engines only have a 3-pin connector for the camshaft sensor. 
• Year of manufacture: VVT was introduced on some 5.3L engines around the 2010 model year. Engines from 2010 and newer are more likely to have VVT, but checking the timing cover is the definitive way to know.