Is there oil pressure problem?

[Cruizer219]

Changed oil then got oil pressure low warning light. Hooked up pneumatic mechanical gauge and found i have about 10psi when at idle at 1k rpms, goes up to 25psi when cruising at 3k or more rpms. Will not go higher than 25psi and is a little lower when warm. Oil is SAE 30 and i changed to mercruiser oil filter but no change in pressure. Unsure if i have a problem? Runs cool, sounds fine. If i take to shop as planned, i will lose the boat for my best, last few weeks of summer! Am also curious if i should try a heavier weight of oil for this old engine.... 1982 mercruiser 140.
Thx for the irreplaceable advice,
Cruizer

 

[Scott Danforth]

you should have a minimum of 10 psi per 1000 RPM. anything less than that is an issue.

since you have only 25psi, that is low.

try running Rotella 15W40. you could have a chunk of dirt in the oil filter bypass check or you could have a bad oil pump or a bearing that has gone south.

 

[harleyman1975]

I have 60 psi at 3500 and 30 at idle (650).