Function and operation principle

The Continuously Variable Valve Timing (CVVT) system controls the amount of valve over-lap or under-lap by varying the amount of oil flow into an assembly mounted on the intake/exhaust camshaft. The ECM controls the oil control valve. As oil is directed into the chambers of the CVVT assembly, the cam phase is changed to suit various performance and emissions requirements.

1. When camshaft rotates engine rotation-wise: Intake-Advance/Exhaust-Retard
2. When camshaft rotates counter engine rotation-wise: Intake-Retard/Exhaust-Advance

Fig 1: Identifying CVVT Oil Control Valve Location

Courtesy of HYUNDAI MOTOR CO.

Fig 2: Identifying CVVT Oil Control Valve Location

Courtesy of HYUNDAI MOTOR CO.