Oil pressure light

[DannyS]

I have a Universal M 25 engine and this past trip on the boat, the oil pressure light came on on my engine's starting panel. I don't have an oil pressure gauge, just a light. I took a good look around my engine and have found no signs of a leak and there's plenty of oil in the engine. The light comes on when I start the motor which according to the manual, is normal, but it doesn't go off until I rev the engine, then it goes off but slowly comes back on after motoring at the higher rpm. It doesn't stay on all the time, it's somewhat intermittent once the engine is warmed up, but I've found it to be on more than it is off.
Any ideas where to start looking?
P.S. I'm no mechanic but I do my own oil changes/filters and winterizing etc.

 

[Ross]

first change the pressure sensor.

 

[RichH]

First put a gage in place of the pressure transducer. If the actual pressure is low you have a problem; if not, its usually the transducer gone bad (usually corrosion that is shorting out the transducer to ground),

 

[rardiH36]

I don't really have first hand knowledge about Universal engine warning systems, but for my 1980 Yanmar, if a warning light goes on, then also the audible alarm goes off simultaneously -- important since who during the day in the sunlight would ever notice a warning light come on? I would think an audible would be the case for any engine brand?

So if your engine warning buzzer is not going off when the light goes, also suspect general wiring harness problems as well as the suggestions already made.

 

[DannyS]

Ok, so I went to the Torreson Marine website and found this doo-hicky (see photo) it's called an "Oil Pressure Switch - Single prong". Is this what you would refer to an oil pressure sensor or pressure transducer?
RichH, where would I find an oil pressure gauge? Would an auto parts store have something that could be added in place of the sensor?

 

[woodster]

danny ...i am not Rich but yes that is the oil switch/transducer in the pic and yes you can go to an auto parts store and find a oil p guage ...if you want to keep both just get a pipe tee the size you need and install both ...hopes this helps...

regards

woody

 

[DannyS]

Thanks woody.

 

[JoeWhite]

oil pressure switch - see the photos. The pressure switch is normally open contact- when there is no pressure. When the oil pressure developes the contacts close and places a short across the buzzer so it can not make any noise. To confirm if the switch is causing a problem - disconnect the two wires from it and jumper it with a short jumper - like the one I have made. Then turn on the engine and see if it works OK. If so then replace the oil pressure switch. If no then replace the 1 K Ohm resistor - see the wiring diagram. The resistor is inside a shrinkable tubing and is next to the fuel lift pump. It is not easy to find. The part number for the oil press switch is 037323. On my engine it started to leak and I lost most of the engine oil. The galley floor was a mess. Good luck. Contact me if I can help baysailor2000@att.net

 

[Don12364]

Ross is right - and he is very kindly trying to protect you from the full horror of the situation.
Engines need a 'decent' oil pressure of about 40psi or more when running under load.
To prevent the light coming on at normal idle, pressure switches are made to operate at about 5psi.
If your switch is not faulty then it could mean your oil pressure does not even reach this under normal running. It can mean your bearings are shot.

Shifty dealers on used car lots sometimes put higher weight of oil in the sump!

 

[JoeWhite]

Oil pressure -

According to the Universal manuals oil pressure guage closes at about 5 PSI

 

[DannyS]

So I got the new oil pressure switch and went up to the boat to change it out but found that it is buried in one of the most inaccessible spots on my boat. I needed a mirror just to see it. I didn't have a socket large enough to get it removed so at this point, I haven't gotten much farther on my project. I did get the wire off and cleaned the lug but the light still came on, wishful thinking that that would help. Anyway, after reading through this and other threads regarding oil pressure sensors, I've seen a lot about a warning buzzer. I have not heard a buzzer nor do I know if I have one. Would that be located on the engine control panel?