What is the cause of a stuck intake VVT operation failure?

[DiDaniel]

Possible causes include damage to the intake VVT valve, clogged oil passages, excessively dirty engine oil, or abnormal engine oil pressure. Relevant explanations are as follows: 1. VVT: VVT (Variable Valve Timing) is one of the popular engine technologies today. It controls the intake and exhaust valves to optimize air distribution and has been increasingly applied in modern vehicles in recent years. 2. Function: The valves are driven by the engine's crankshaft via the camshaft, and the valve timing depends on the camshaft's angle. In conventional engines, the opening and closing times of the intake and exhaust valves are fixed, making it difficult to meet the engine's demands at different speeds. VVT effectively resolves this contradiction.