Dear all: I posted this question a few days ago on the Marine Diesel Direct board, a terrific site, but they are not always too quick to respond. I wondered if anyone here has any thoughts about this. Thanks very much in advance for your input! This past weekend we were out on our boat (1986 O'Day 272) for the first extended trip of the year. This is my fourth season with the boat, and have had no serious engine problems to date. Engine has about 700 hours on it. Saturday, after four hours of continuous motoring (no wind, 90+ degrees), as we slowed to enter an anchorage (going from 2700 rpm +/- to perhaps 1200), I noticed the oil pressure alarm sounding weakly. At first I was not even sure what it was. Throughout, the guages indicated about 40-45 lbs pressure, which has always been the case, and about 185 degrees of engine temp. Felt cooling water coming out of transom exhaust and it was not hot. When I'd rev the engine higher I could get the alarm to cease. When we anchored I checked oil and it was about 1/2 quart low. I added that much the next morning. Throughout the day of again motoring for a few hours, the alarm was still there, but still soft. I seemed to notice that on the return trip, in 2 foot swells, the alarm would sometimes sound when we were dropping down from a swell, and cease or dimish on the "uphill" ride. The oil I've been using is 15W-40. Is my oil pressure in the OK range? Does this sound like a bad sender? Could it be a ground connection to the sender?
