1999 Mercury 90 hp Question?

[Rod & Reel]

I have a 90 hp Mercury on my pontoon boat. The oil warning buzzer came on while I was motoring across the Lake. I killed the engine and filled the oil resevoir with oil and started the engine. Once before when it was low of oil, I filled the oil tank and the buzzer quit. This time the buzzer stays on. When you turn the key on, it starts buzzing before you crank it. I was told that my oil tank could have gone bad (there is supposed to be a float or sensor in tank and I would have to replace the whole tank). Someone else said there was somekind of module on the side of the motor that might be bad. Was wondering if anyone has had the same problem in the past and might offer some suggestions before I carry it to a dealer to be fixed. Thanks for any reply or suggestions. R & R

[ky-slabseeker]

Inside of your oil tank there is a float whic lies down in the bottom corner of the tank.. And in the bottom of the tank there is a sensor that slides up in the bottom.You will have to replace the oil tank if you cant get the float unstuck inside of the oil tank.I have changed quite a few of these when I was turning wrenches in the past.It is not a bad job to do at all. Or you can just unhook the sensor and leave it at that.But if you do this you will have no low oil warning !!!! You will be better of replacing the tank in my opinion... I hope this help you out some.....

[gary]

Hey Rod& Reel The warning horn is connected to the oil injection system and the temperature sensor. A problem with the oil injection system,the horn will sound in a intermittant beeping sound. overheat condition is indicated by a continuous beeping sound. If the horn stays on when the ignition key is turned to ON the engine overheat sensor is the possible cause. Disconnect the sensor{BLACK wire}and try again turn key to ON . no sound replace sensor.If horn sounds continuous beep,module is faulty. GaryI

[gary]

If the horn is intermittent disconnect the low oil sensor leads{light blue} at the oil tank. connect a ohmmeter between leads going into tank,there should be no continuity.Continuity=bad sensor in tank. No continuity= bad module Hope this helps. GaryI

[ky-slabseeker]

If the horn is intermittent disconnect the low oil sensor leads{light blue} at the oil tank. connect a ohmmeter between leads going into tank,there should be no continuity.Continuity=bad sensor in tank. No continuity= bad module Hope this helps. GaryI

I have a 2000 model merc 75hp and when my oil gets low I have a steady warning tone not an intermediate tone.......... Chances are the float will be stuck not a sensor bad....