Yanmar 370 Oil Pressure

[aviator7836]

Hello all,

I have a 2004 MS Pilot 43 with a single Yanmar 6LYA-STP 370HP engine. Today I noticed something that concerned me relative to oil pressure and wanted to check with others about their experience.

In the past, my memory was that as soon as the engine started the oil pressure went straight to approx. 75 psi regardless of engine RPM and stayed there throughout operation. Today, at idle the oil pressure was only about 30 psi, perhaps 40 psi at 1000 RPM, and increased to the usual 75 psi or so as RPM was increased toward operating speed. This seemed out of the norm from my prior experience with the boat.

Can others please tell me what your indicated engine oil pressure is and whether it is always at the 75-80 psi operating pressure regardless of engine RPM or whether it is highly variable based on engine speed?

I just want to figure out if I have a pending oil pressure problem (pressure regulator, looming pump failure, or the like).

Thanks in advance for you experience and expertise!

Doug

 

[Duetto]

hi, we have a 2003 pilot 370 yanmar. our oil pressure is pretty much as you describe, once started it's always high. with that said my mechanics side says 30-40 psi at idle is not problem. the bigger issue is the change in behaviour. i would keep a watch on it and see if this is the "new normal" or it's the start of a problem.

good luck.

 

[rgano]

hi, we have a 2003 pilot 370 yanmar. our oil pressure is pretty much as you describe, once started it's always high. with that said my mechanics side says 30-40 psi at idle is not problem. the bigger issue is the change in behaviour. i would keep a watch on it and see if this is the "new normal" or it's the start of a problem.

good luck.

My 315 HP Yanmar 6LPA-STP with less than a thousand hours on it registers maybe 40 PSI at startup and then subsides to somewhat less pressure, maybe 25-30 once it is well warmed at idle. I typically runs 60 PSI up on plane at around 2900-3000 RPM.

I would say your gauge reading 75 PSI all the time was unusual and that it is now operating properly. I do not have a lot of faith in the Faria cluster gauge Mainship put in these boats,

 

[Shrew]

I would say your gauge reading 75 PSI all the time was unusual and that it is now operating properly. I do not have a lot of faith in the Faria cluster gauge Mainship put in these boats,

I have a Yanmar 6LPA-STP2 (315HP) and that is how mine has always worked as well. I have a friend with a Cummins and another with a Cat and both do the same too.

[General Statement] Incidentally, the vessel and the engine HP are basically irrelevant. What really matters is the engine Make and Model.