Dave walden
New member
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 ?