Low oil warning alarm

[Red Shad]

I have a 90 Mercury. The low oil alarm went off today. After adding oil to the injector tank the alarm should reset once the motor is restarted. It did not. Is there a manual reset for this alarm? Any advise will be helpful. Thanks

[TritonKTB]

Check the oil resevoir under the cowl on the side of the motor.

[fisheater]

Turn off your main power switch and your key then you can start it and the alarm should not be there.

[RANGER519]

if this doesn't fix it take the part that the line that goes to the motor out of the oil tank ,it will be a stem or pipe like it has a screen at the bottom wash it off in gas . this screen gets dirty sometimes & causes the oil buzzer to go off.

ranger519

[buzzking]

also, if you take the lid off of the reserve tank on the motor, you break the vacuum in it...you may have to take it in to the shop to get someone to purge the air out of that tank so it will achieve vacuum again. The alarm will stay on until it gets purged correctly.

[crazyfishinnut]

In a outing last year my 115 mercury started sounding that horn. it had planty of oil ,water pressure,and was not hot. Renegade marine fixed it. The sending unit that is in my oil tank went bad. they repaced my tank and sending unit.

[Fisherjoe]

Had the same problem and it was a bad sending unit. Mechanic told me bottom of oil tank was cruddy and fouled the sensor. He asked if I always kept the tank topped off or if I let it run almost empty before refilling. I said topped off and he said not to do that anymore. By letting the tank run low before filling, it helps prevent settling in the bottom of the tank.

Joe

[F16ENGMGR]

Hey Joe,

What settles in the bottom of the tank? I use synthetic oil and besides, the system is closed. Interesting but I'd need to see service bulletin on this. I had a similar problem with low oil warning sending unit maybe 10 hrs ago. Took boat in because of audible alarm at throttle quadrant. No/low water pressure and didn't know it but had to replace oil sending unit. Yr 02 - 175 Merc Opti Max - Run Time 257 Hrs - Fuel Used 1029 gallons

F16

[Fisherjoe]

I assume impurities, or the oil itself, settles. By always staying topped off, the mechanic said the oil at the bottom of the reservoir never stirs around and will build up on the sensor. He stated that if I would run the tank low before filling, it would keep anything from building up on the bottom of the tank. May not be a problem with synthetic.