I have a Volvo Pent SX 4.3l from 2008. Recently I have notices a grumbling type noise when taking hard turns at 25 mph to 30 mph. The noise starts when the helm is about halfway, or more, to the wheel lock (wheel stop). At high speed (40 mph to 50 mph), I could not hear the noise. The power steering fluid reservoir looks to be full. The boat has less then 150 hours on it. Can someone help? Thanks, Jake