Mariner 150 - constant beep but oil is fine ?

[Gnirts]

Ive done a search on this and found a few similar threads but the solutions offered there dont seem to help here so starting a new thread.<br /><br />We've got a Mariner 150 engine, 6 cyl roughly 10 years old bought a few months ago.<br /><br />The last 2 months or so we've got a constant beeping noise when the engine is running or when stalled with ignition still on. This happens both in and out of gear.<br /><br />The manual says this is an oil alarm.<br /><br />The boat has an external 2 gallon container which is full and contains no oil sensor.<br /><br />The reservoir in the engine is full.<br /><br />The engine itself is working, is taking oil, temperature is fine and so on<br /><br />We've tried disconnecting the blue wire from the sensor on the internal tank but the buzzing remains. This is where it differs from the other threads as they seem to hint that it should stop the beeping.<br /><br />Can anyone suggest something else to try to fix as the noise is getting incredibly irritating.<br /><br />Could it be some sort of short in the console or can the beep noise mean another problem that isnt oil ?

 

[WillyBWright]

Re: Mariner 150 - constant beep but oil is fine ?

Welcome to iboats.<br /><br />A constant tone should be an overheat alarm. Oil warnings are like beep beep beep... The oil warning has two sensors. One in the small oil tank on the motor, the other is a motion sensor for the pump drive gear.<br /><br />If the constant beep is coming on when the motor is warm or cold, the problem is a shorted overheat sensor, wire, or a bad warning module. You can check for a bad sensor by unplugging the tan/blue wire on each cylinder. If the alarm stops, that's it. Shorts are best found by wiggling wires and listening for changes in the tone. There is no test for the module.

 

[Gnirts]

Re: Mariner 150 - constant beep but oil is fine ?

Its a beep not constant tone that sounds like the oil alarm (we had it for real a while before this problem started).<br /><br />Disconnecting the blue coloured wire coming from the small tank didnt stop the beep (theres a blue and brown coming from it).<br /><br />The tone of beep changes when you touch the trim up/down controls on the console (quicksilver if it matters)

 

[WillyBWright]

Re: Mariner 150 - constant beep but oil is fine ?

So it goes beep beep beep, and not beeeeeeep? Okay, that's the oil. Make sure the small tank is absolutely full, right up to overflowing. There should be no air in there at all. Add oil to your gas to 50:1 until you get this worked out just to be safe. The plastic drive gear could be failing, but still working somewhat. The warning module is working, so that isn't the problem. Tone change when trimming is normal. The trim system is quite a draw on the power.<br /><br />There is a magnet in the oil pump drive coupler. On early models these can fail. As it passes the motion sensor it generates a tiny amount of voltage as the signal to the warning module. It might be worth removing the oil pump and checking the condition of the components. If you have slivers of gray plastic in there, your drive gear is failing. You can also see it by looking in the hole with a flashlight and turning the flywheel. If the gear is bad, the motor has to come apart to replace it. If you'd rather switch to premixing your gas and oil, we can help you with that. It's not difficult, but there are procedures you have to follow.

 

[dingbat]

Re: Mariner 150 - constant beep but oil is fine ?

Check the ignition coil lead connections on the ignition switch. Determine the coil lead having the green wire connected to it. You should have 12 volts on this wire. If correct, the module is getting the correct current.<br /><br />Disconnect both low oil sensors from the terminal connectors. Do not remove the cap from the reservoir. Connect ohm meter between the leads and check for no continuity. If continuity is present the sensor is faulty.<br /><br />Disconnect white wire from the module and check voltage. Voltage should be 12 volts pus or minus one volt. Next, reconnect the white lead to the module and insert the probe into the white wire for voltage checks. Check output of voltage to sensor by connecting voltmeter to blue/white sensor plug leads. Remove plug wires and turn ignition on. Now rotate motor and watch for voltage output on the meter. The voltage should be 5 volts plus or minus one and then drop to less than one volt every two revolutions of the flywheel. If no voltage exists them you have either a bad sensor or a bad drive pump.

 

[Gnirts]

Re: Mariner 150 - constant beep but oil is fine ?

OK, been at the boat all day so havent had a chance to check the replies posted today but heres what we did today.<br /><br />Firstly checked the float sensor on the oil reservoir, it works perfectly breaking the circuit when full and closed circuit at any other level.<br /><br />We've traced the wires going into what i assume is a sensor module, a sealed black box labelled "414?0A14 / 3410"<br /><br />We tried to short the oil float switch sensor to earth and no difference, tried with various combinations of wires disconnected and reconnected but still no stopping the beeping.<br /><br />The very odd thing now, the wires are reconnected exactly as original and no beeping at all, including the ones its MEANT to have (the pre start beeeep beep beep) so assume something has been loose and knocked (?)<br /><br />We know the oil pump is working, using and mixing oil, we know the internal reservoir is full and its float switch is working so that leaves either the sensor in the pump or the module itself.<br /><br />Will try dingbats suggestion on the weekend to try to narrow it down.