How Often Should Valve Stem Seals Be Replaced?

[VanSophie]

Valve stem seals generally need to be replaced every 20,000 to 30,000 kilometers. Valve stem seals are a type of oil seal, typically composed of an outer frame and fluororubber vulcanized together. The seal's inner diameter is equipped with a self-tightening spring or steel wire, designed to seal the engine valve guide. Valve stem seals prevent engine oil from entering the intake and exhaust pipes, thereby avoiding oil loss, preventing the leakage of the air-fuel mixture and exhaust gases, and stopping engine oil from entering the combustion chamber. As a critical component of the engine's valve train, valve stem seals are usually made of fluororubber. Over time and under the influence of alternating working temperatures, rubber components lose their plasticizers. Damaged valve stem seals can cause the engine to burn oil, resulting in blue smoke during cold starts, along with symptoms like poor acceleration and engine vibration.