Abstract: Oil leakage of engine cylinder head cover is one of the important problems that influences the engine performance and the overall vehicle performance. In this paper, the principle of cylinder head cover permeability was studied. And the influencing factors affecting the performance of the head cover sealing deformation forms, gaskets structural design and hardness, bolt preload and other major factors were analyzed systematically. Finally, the anti-leakage solutions were proposed.

Key words: thermoplastic cylinder head cover, seal, prevent oil leakage