4lhdte oil pressure

I have a 27 foot tiara with twin yanmar 4lh-dte engines. When I start up both engines register oil pressure just over 2 kg/ cm2. When I throttle up both rise to just above 6 kg/cm2. Normal so far. As oil heats up port lowers to just below 6 kg/cm2 while stud slowly lowers to just above 4 kg/cm2. When I pull back to idle port drops to just above 2 kg/cm2 while stbd drops to 1 kg/cm2. Both engines previously tracked like port engine. As stbd seems to track normal when cold and powering up and readings do not seem erratic I do not suspect mechanical sending unit. Is my stbd oil pump getting ready to fail ? Any ideas of cause ?

Hello Dave,
The oil senders on these gauges on the Yanmars are not the greatest. Many complaints. They just read low and your readings are good from what I recall. There is a service bulletin on that issue. To give you a piece of mind take a oil pressure gauge, capillary type. That is a gauge with a tube, not electrical and take a reading of both engines. That will tell you what they do real in PSI Check your service manual. If you do not have one, get one it is a good educational read.
Happy sailing