Oil pressure, the most fundamental to engine's performance and longevity, is critical as it ensures that the engine components are properly lubricated, cooled, and protected against wear and contamination, ultimately contributing to reliable engine performance. Due to several factors of engine, such as speed and load, there are fluctuations in oil pressure, which can be controllable and sometimes unpredictable. Controlled oil pressure fluctuations are essential for engine efficiency and adaptability, such as adaptive lubrication, temperature compensation, and hydraulic component functioning like variable valve timing, VVT, and hydraulic lash adjuster, HLA. But excessive or irregular fluctuations can indicate serious issues like excessive or sudden drops, unstable engine performance, valve train noise, improper lifter operation, VVT malfunctions, overheating, and increased wear.
In this paper, HLA gallery pressure fluctuations are studied, and its impact was assessed on valve train system. Root cause analysis (RCA) was conducted using high frequency oil pressure measurement to understand the various reasons impacting high oil pressure fluctuations inside HLA gallery. Time domain analysis was performed to understand oil pressure fluctuations with respect to VVT cam phasing. Angle domain analysis was performed to assess the impact of oil pressure fluctuations on valve train components. Further findings from this study aim to enhance the understanding of impact of VVT cam phasing in oil pressure fluctuations.