What Causes Volvo Variable Valve Timing Unit Failure?

Do you know what a VVT Unit is and what makes it fail? The variable valve timing (VVT) unit in Volvo is a component that adjusts the timing of the valves’ opening and closing. In most Volvo models, the VVT unit is found near the top of the engine, often attached to the cylinder head. It works by altering the position of the camshaft relative to the drive gear, changing the timing of valve operation based on engine load, speed, and temperature.

When those changes are made perfectly on time, your engine runs more efficiently, leading to more power, better fuel economy, and reduced emissions. However, like any mechanical system, the VVT unit is prone to wear and failure over time.

Factors That Can Lead to VVT Unit Failure in Volvo

• Temperature Extremes: VVT systems are designed to operate within certain temperature ranges. In cold conditions, oil can thicken, making it harder to circulate through the VVT unit, thus hindering its operation. If you live or drive where it gets really hot, your oil can degrade faster, which causes it to lose its lubricating properties. Whether too cold or too hot, neither is good for the VVT system.
• Oil Quality and Change Frequency: The VVT system in Volvo cars relies heavily on the quality and condition of the engine oil. High-quality oil ensures proper lubrication and functioning of the VVT components. However, even the most high-quality oil will degrade over time. The oil will turn into sludge thanks to heat and contaminants, and that sludge can stop up the VVT unit, restricting oil flow and leading to malfunctions or complete failure.
• Engine Oil Level Fluctuations: The correct oil level is essential for the smooth operation of the VVT system. When the oil is too low, the system is not lubricated enough, meaning the VVT system experiences more friction and heat. When there is too much oil, it can cause too much pressure in the system, which can cause the oil to foam. Both scenarios are detrimental to the VVT unit, as they can cause it to operate inefficiently or fail prematurely.
• Faulty Solenoids: The VVT solenoid is an electrical component that controls the flow of oil to the camshaft-phasers. When the engine’s control unit sends a signal, the solenoid’s electromagnetic coil is energized, moving the oil control valve. A malfunctioning solenoid can disrupt the flow of oil, leading to improper operation of the VVT system.
• Electrical Issues: The VVT system’s operation is partly controlled by electrical signals. Faulty wiring or poor connections can disrupt these signals, leading to erratic operation of the VVT solenoid and the entire system.

Preventative Measures and Maintenance Tips

• Regular Oil Changes: Regular oil changes remove contaminants and prevent the buildup of sludge, which can clog the tiny passages inside the VVT unit. Follow the Volvo manufacturer’s recommended intervals for oil changes. You can also speak with your mechanic about your driving habits, and they can help determine the best time to change your oil. Also, use high-quality oil that meets the specifications of your specific Volvo model. The correct oil ensures proper lubrication and has the right additives to keep the engine and VVT system clean and functioning optimally.
• Monitor Engine Performance: VVT is responsible for optimizing valve timing for better performance and efficiency, so issues with this system can manifest as engine performance problems. Be alert to symptoms like rough idling, loss of power, decreased fuel efficiency, or unusual noises from the engine.
• Professional Diagnostics: Some VVT system issues may not be apparent or easily diagnosable without specialized tools and expertise. If you suspect a VVT-related issue or notice any of the symptoms mentioned earlier, it’s wise to consult a professional mechanic.

Let Our Expert Mechanics Resolve Your Volvo’s VVT Issues

When your Volvo’s VVT is acting up in Dallas, TX, Southwest Auto is here to help. We have years of service under our belt, so we can handle any issue your Volvo can throw at us. If you live in or around Dallas, TX, call or stop by to learn more about how we can help get your Volvo back in top shape.

* White Volvo SUV image credit goes to: Wirestock.