Most modern engines have variable valve timing (VVT), a feature designed to change an engine valve timing. Like other systems, the VVT system has several parts, which can fail or develop issues over time. Understanding this system can be tricky, and questions can arise quite frequently. In this article, we’ll answer some frequently asked questions regarding the VVT system.
Engine valves open and close at precise intervals, allowing the combustion chamber to pull in and push out air. Changing the valve’s timing can profoundly impact an engine’s characteristics, making it more powerful or fuel-efficient, depending on the driver’s inputs.
A component called the camshaft spins and its lobe shape pushes the valves open and close at a precise interval. Controlling the valve timing involves changing how and when the camshaft pushes the valves.
Yes. The variable valve timing system controls the valve timing by manipulating the camshaft. A component called the camshaft phaser changes the camshaft’s position to change the engine’s timing. This camshaft phaser is located at the end of the camshaft, near the timing belt.
The variable valve timing solenoid controls oil flow in the conduit leading to the camshaft phaser. The cam phaser rotates the camshaft to either advance or delay the valve timing depending on whether the VVT solenoid allows or cuts off oil flow.
VVT solenoid failure is quite common. A solenoid typically fails because of wear and tear. When this happens, the solenoid can get stuck in one position or can’t conduct current. The only way to fix a failed solenoid is to replace it. VVT solenoids can also fail when a vehicle overheats.
Replacing a VVT solenoid can take anywhere from one to three hours, depending on its accessibility and the number of solenoids that need to be replaced.
Replacing the VVT solenoid involves removing the engine cover, which exposes the cylinder head and valvetrain components. Most VVT solenoids are mounted on top of the cylinder head, and removing them involves unscrewing some bolts.
Most modern vehicle engines have VVT because of the technology’s many benefits. However, most vehicle manufacturers call their VVT systems with different names.
For example, Audi has Valvelift, Toyota has Variable Valve Timing with Intelligence, and Honda has their famous VTEC, which stands for variable valve timing and lift electronic control.
Most vehicle manufacturers also have a unique name for their VVT systems since they aren’t identical. For example, Honda’s VTEC has variable valve timing and variable valve lift, which also changes how far the valves lift. Meanwhile, some manufacturers only do variable valve timing.
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