I have a 1996 proline with a 260 merc i/o. I have been hearing a high pitched sound that goes on every now and then and drives me nuts. I think its my low oil pressure alarm but my oil pressure is 40+ pounds all the time. Water temp 150-160 mostly 150. The alarm only goes off under 1000 rpms. And it goes on and off. Its not constant. I think its a corroded wire, but dont no where the alarm is located. Has this happend to anyone before? Casn anyone help me. :confused:

Does this happen all the time or just after a high speed run. Oil pressure after a high speed run will be low until oil temp drops and brings back your pressure. Hence good to bring the throttle down slow.

If not. Locate your oil sender unit. Located on various spots on diffentent model engine. Very small screws in with 1/8" pipe thread. This just for your gauge. The alarm is probably generated from a factory set pressure switch which may me right next to sender. Also very small, will fit in the palm of your hand. Since your pressure seems to stay at 40....This pressure switch may be going bad or the wires going to it are corroded or both.

Hope you find it, Jon

lower unit resavior tank might have an alarm on it too.

It was the lower unit resevoir. Filled it up and good to go.