I'm thinking of replacing my oil reservoir, in my boat. The question is, do I need to, or is it ok? What it does, is when the engine is running (XR6 150), I hear a pulsing sound coming from the container, it's almost like a hissing. There are two hoses attatched to it, one coming from the motor, and one feeding the oil to the onboard reservoir, on top of the engine. I know, that the motor pressurizes the container, to maintain the flow, but should I hear that pulsing sound? Or is there a leak? I made sure the cap was as tight as I could get it. It's been doing this for as long as I can remember, and I don't think the oil flow, has ever been interupted, but I also notice an oily film all around the container, and surrounding area. Any suggestions?