Main Engine Oil PSI gauge keeps climbing?
On my way back from Catalina, I noticed my main engine oil PSI gauge kept climbing. It normally runs at around 60 PSI. It started climbing gradually over about an hour and got up to over 125 PSI. I shut that motor down for 15 mins then started it back up. Registered 60 PSI, then started gradually climbing again to 125 PSI. Oil level is fine.
They are 1985 Volvo Penta turbo diesels 235 hp with only 1100 hrs.
The other motor is fine. Runs a steady PSI.
I can't figure out what might be the issue.