Yanmar Oil Pressure

[hughesj]

I run dual Yanmar 4LHA-STE engines in a Mainship 390 Trawler – they have approx 470 hours on them
My oil pressure gauges have nominally run around the 60 to 70 PSI
One engine is experiencing a drop in oil pressure to 30 PSI
At what pressure does the low oil pressure alarm activate and is there a nominal pressure at which I should consider shutting the engine down prior to the alarm activating.
Thanks
John

 

[Moonstruck]

I run dual Yanmar 4LHA-STE engines in a Mainship 390 Trawler – they have approx 470 hours on them
My oil pressure gauges have nominally run around the 60 to 70 PSI
One engine is experiencing a drop in oil pressure to 30 PSI
At what pressure does the low oil pressure alarm activate and is there a nominal pressure at which I should consider shutting the engine down prior to the alarm activating.
Thanks
John

I have no idea what level the alarm is set for. I do know that the engine needs a good oil flow. I would quickly give the gauge a check. You could possibly switch the wires to the gauges temporarily to see if you get the same result. You can also switch the senders if the result is the same. Hopefully the problem is with a gauge or sender. Get it checked out before losing a very expensive engine. I would not run it until I knew what was going on. An oil pump is expensive, but nothing like an engine.

Oh year, check for a solid ground connection at the gauge. You may not be getting all the current required.

 

[SteveH]

I recently had an oil pressure indication problem with my Yanmar 160 4LHA-HTP. The wire at the bottom of the oil pressure sending unit was stretched so tight to the Yanmar wire harness that it had in time broken down to only a few strands of connection. I guess the electrical resistance of only a few strands of wire leading to the sending unit circuit cause low and erratic oil pressure indications. After giving the wire some slack and reconnecting with a full wire conduction, all was good. Might be a place to start.

SteveH