mariner 40hp oil sensor question

[kuks24]

I took the oil tank sensor wires apart and I measured ohms across them, going to the tank and it was zero ohms, like a short, and I measured a new switch that measured the same, should it measure infinite ohms, like an open when the oil tank is full. I am getting an solid alarm on high RPMs and was wondering if that is the problem

 

[saumon]

Re: mariner 40hp oil sensor question

Yes, there should be no continuity when the thank is full (circuit open). But the problem isn't the sensor (or swith), it's usually the magnet inside the tank. It is attached to a floater and slide up and down as the oil level change, but it happen that it separate from the floater and always stay on the bottom of the tank, creating a continuous alarm.

To test it, empty your tank, connect the two blue leads, turn the key to the ?on? position and flip the tank upside down. If the alarm stop when the tank is reversed, your magnet has fallen and there's no other choice than a new tank...

This is for the magnet problem but i can't understand why you're getting the alarm only on high rpm?

 

[kuks24]

Re: mariner 40hp oil sensor question

Yes, there should be no continuity when the thank is full (circuit open). But the problem isn't the sensor (or swith), it's usually the magnet inside the tank. It is attached to a floater and slide up and down as the oil level change, but it happen that it separate from the floater and always stay on the bottom of the tank, creating a continuous alarm.

To test it, empty your tank, connect the two blue leads, turn the key to the ?on? position and flip the tank upside down. If the alarm stop when the tank is reversed, your magnet has fallen and there's no other choice than a new tank...

This is for the magnet problem but i can't understand why you're getting the alarm only on high rpm?

Yeah, I can idle all day on the motor and never hear that sound, but as soon as I get a little above idle or full throttle, it sounds, it is really weird.

 

[Moody Blue]

Re: mariner 40hp oil sensor question

It's been a while since I've owned a motor like yours but if I remember correctly, the solid alarm is a temp overheat alarm. An intermittent alarm is the low oil alarm.

That would make sense if you are only getting an alarm above idle. Time to replace your waterpump impeller.

 

[kuks24]

Re: mariner 40hp oil sensor question

It's been a while since I've owned a motor like yours but if I remember correctly, the solid alarm is a temp overheat alarm. An intermittent alarm is the low oil alarm.

That would make sense if you are only getting an alarm above idle. Time to replace your waterpump impeller.

I already did replace the impeller, and I still get the alarm, and to go with the constant or intermittent, I read that somewhere too but everybody is telling me more about oil alarm

 

[Moody Blue]

Re: mariner 40hp oil sensor question

If you keep running the motor with that (overheat) alarm going off you will be posting back here soon asking how to rebuild the powerhead. If you have a new impeller, then something else is wrong. Maybe misaligned water intake tube or partially blocked cooling passages. Better investigate before its to late.

You have another thread on this same topic here also

http://forums.iboats.com/showthread.php?t=454680&p=3065060#post3065060

Your motor does not have a thermostat or poppet valve.