PCV valve flutter : vibration characterization through pressure and flow

Abstract

A Positive Crankcase Ventilation, or PCV, valve is required by internal combustion engines in order to regulate the flow of blow-by gases out of the crankcase and into the intake air stream. Fluctuations in the pressure and flow of these gases lead to poor performance and can be detrimental to engine durability. This thesis addresses a specific case of PCV valve component vibration, or flutter, which in certain conditions has been severe enough to be perceived by the customer. Tests monitoring pressure and flow were performed in a variety of test setups in order to simulate every real-world scenario possible at the bench level. Data attained was analyzed in order to identify and characterize any and all patterns in pressure and flow indicative of flutter conditions. The end result of this thesis is summarized in a recommended test procedure to be followed in future cases of PCV valve flutter.