"josZ" wrote in message
t...
The oil pressure in my engine, a volvo penta 3.0gs from 1996, is gone
above 3800 when the engine is hot. I use multigrade 10w40 oil. What could
be the problem?


If your engine has bad mains or rod bearings then oil will be slung out of
the bearings at higher RPMs and your oil pressure will drop. You should
hear the rod bearing as a low pitched ticking at idle with hot oil. High
pitched ticking is generally the valve train. If you had a car I'd tell you
to put the car in gear, put one foot on the brake and press down on the
throttle slightly. If the rod bearings are bad then you would feel/hear the
slap of the rods.

You should be using a 20w40 oil in any case.

At this point you can probably pull the engine and replace the ROD bearings
(they cost about $90) and mains very easily. Just remove the oil pan. I
did my dodge van (318 V8) in two hours from lift to drop. I didn't have to
pull the engine but did have to remove parts of my tailpipe. It took more
time to remove the tailpipe than to replace the rod bearings.

Before bearing replacement I had 40 pounds oil pressure cold, 15 pounds hot
at idle. When hot I had ticking (slap) of bad rod bearings at idle. Oil
pressure hot was 40 pounds at speed.

After replacement of bearings and oil pump, 40 pounds cold, 40 pounds hot at
idle and 55 pounds hot at speed.