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Volvo Penta MD 7A high oil pressure?
I'm still new to diesel motors. In May 2006, I bought a 1965 sailboat with a 1984 (or so) Volvo Penta MD 7A in it. I used the boat all that summer with the only motor problems having to do with the starter (the former owner paid to have it re-build), the ignition switch (I installed a new one) and air in the fuel line (a longer story).
Since I needed to work on other projects on my "new" forty-year-old boat, the motor wasn't started for about 31 months. During that time I did fill it with antifreeze. I also drained and cleaned the fuel tank and pulled it to repair a few small leaks in it. This spring I re-launched, replaced the return fuel line from motor to tank (because it looked real old), cleaned the fuel strainer on the fuel pump, changed the fuel filter and learned how to bleed the fuel line. The motor started without trouble. After warming it up I changed the motor oil and filter.
This summer I've used the motor mostly (short 10 to 20 minutes at a time) to get out of and back in the mooring box, with two longer motor trips; one of them about two hours. It starts and runs fine, but I have noticed that the oil pressure gauge reads higher than what the manual says it should. After starting it quickly goes around 44 to 50 psi at idle and goes over 60 psi at a fast idle (about half throttle, out of gear). Under load it doesn't get much higher but that's near the top of the meter's range anyway. (Three years ago, I didn't know what it was supposed to read and didn't pay much attention, since it didn't read low and the alarm didn't sound.) I don't know how to verify if the meter is accurate but did check the voltage on both sides of the sender and it seems to be fairly constant 12.5 V (approximately) on one side with the other side changing voltage at higher rpm. This seems to me to say that the meter reading is not being affected by higher alternator output at higher rpm.
So my question is, how high is too high and when should I be concerned enough to spend money on getting the meter reading verified, or is there some reasonable way I can do it myself.
I like sailing a lot better than working on the motor.