ONAN 9.0 KW Generator Oil Preasure

[1000islander]

I noticed during our trip last week that my generator oil presure had pegged the guage @ 100. I checked the oil and all seemed to be operationf fine. I assumed that the sending unit or the guage was bad. After our return I checked the connections (removed and re-tighted them) the presure now registers approx 75 when the generator is "cold". Does anyone know what the correct preasure should be? I checked online and can't seem to fined what it should be.

 

[aquadancer]

This is a generic answer, but based on a discussion I had with a reputable diesel mechanic, 1800 rpm diesel engine (your genny motor is most likely turning 1800 rpm) should hold oil pressure between 40 - 55 psi. My Westerbeke oil pressure is steady around 40 psi. Per Westerbeke, low oil pressure safety switch is set at 20 psi.

 

[1000islander]

Thanks, I am assuming the sending unit is bad., due to the change after I reconnected the sender wire. I will try replacing it.

 

[aquadancer]

You may also check the oil pressure relief valve. If it is stuck closed, oil pressure will ped the gauge.