What is VVT? What is the VVT system? What is a camshaft actuator (actuator) and how does it work? What are the signs of an actuator failure?
Nearly all modern vehicles have Variable Valve Timing technology (VVT). This technology was developed in the early 2000s, but its work started in 1991. It is designed to solve the old dilemma of engine design. You prefer to drive gentle and friendly, or forcefully and aggressively? You can use the vehicle in both directions thanks to the VVT. Depending on the configuration of the VVT, this technology may improve engine performance, reduce emission, increase fuel economy or all of these.
The heart of the VVT is made up one or more camshaft positioners (also known as camshaft actuators). When the conditions are right, these actuators change the position of camshafts to adjust engine timing.
Camshaft positioners are great in theory but they can cause engine failures. It is helpful to be prepared for any future malfunctions and to have information on malfunction symptoms.
What is a Camshaft Positioner?
Camshaft positioner, an on-board computer controlled sprocket, controls the camshaft. This gear’s primary function is to adjust camshaft position relative the crankshaft position, changing the valve timing. Manufacturers refer to their camshaft positioners as “camshaft positioningers”. Actuators Or “phasers” Some use different terminology, others use the same. They all serve the same purpose, regardless of their names.
Understanding the basics of the subject is key.
How do Camshaft(s), Valves and Camshafts Work?
One or more camshafts and a crankshaft are found inside the engine. The camshafts operate a series valves that allow air, and fuel, to enter and exit the engine.
The crankshaft drives the piston rods. The intake valves allow air into the cylinders to mix with the fuel when the vehicle is in motion. The spark plugs ignite the mixture and produce a series of small explosions. To let out the exhaust gasses, the piston in which the explosion occurs is forced down.
The crankshaft transmits power from the engine to the pistons at the first start-up. However, now the crankshaft is rotating and the vehicle can be ready to go.
The timing chain, or timing belt, connects the crankshaft and the camshafts. The shafts need to be in sync when the pistons reach their desired point so that the valves will open and close.
How Actuators and Variable Valve Timing are Different
The valve timing in a conventional engine is fixed. The position of the camshaft(s), however, can be changed with modern VVT systems. The valve timing can also be adjusted with modern VVT systems. This can improve engine performance, fuel economy, and/or both.
It is crucial to understand this sentence in order to fully appreciate VVT’s efficiency:
An engine requires more air at high revs. The intake valves that close too soon before enough air enters can cause performance problems. If the intake valves remain open for longer than required at low revs, it can lead to unburned fuel, which will result in poor engine performance. This is how engines that have fixed valve timing function. VVT technology engines, on the contrary, allows the valves to adjust continuously to match the engine’s speed. The timing is optimized for all engine speeds and conditions.
To control valve timing, the camshaft positioner (actuator), works in conjunction with it. The opening and closing valves are controlled by the timing of the engine’s operation. The actuators can be found on the intake or exhaust cam gears. They are connected by a chain.
A VVT solenoid is an oil control valve that applies oil pressure in order to activate the actuator. The VVT solenoids are controlled by the on-board computer (ECM/PCM/ECU) according to inputs from different sensors.
What are the symptoms of a failed camshaft positioner?
- – Illumination and control of the check engine light
- – Reduced engine performance
- – Engine makes clicking noises
- The timing system may be disrupted and the engine could run irregularly or not at all.
- Engine may stall, or stall
- – Increased fuel use
