I have reviewed almost every thread that I can find on oil pressure and none of them address the issue that I am having. I have a remanufactured mercury 5.7 EFI with a Bravo 3 outdrive. The motor has about 80 hours on it, I will state I have changed the oil twice (mercury oil per manual), the oil filter 3 xs and verified the readings with a mechanical gauge.
I start the motor and I have 40 lbs of oil pressure, if I let it idle the pressure will drop down to about 20 lbs at idle, but pop up to 30 lbs at 1000 rpm. It will do this all day if I never go above 1200 rpms or so. If I take the boat up to cruise at 3200 rpm it will have 40 lbs of oil pressure the entire time I am at 3200 rpm. If I stay at 3200 rpm for 2 minutes or 22 minutes still 40 lbs of pressure, the moment I slow down the oil pressure drops to about 5 psi at 1000 rpm and 0 on the gauge at idle. If I start back up to 3200 rpm it will come back up to 25 lbs, but never to 40 lbs.
If I run to 3200 rpm for 1 minute it does the same thing. I appear to lose all pressure the second I slow down after cruising regardless of how long I cruise, if I shut the motor off and wait an hour I can duplicate the result, whatever the issue is it resets itself after sitting.
Any Ideas?
I start the motor and I have 40 lbs of oil pressure, if I let it idle the pressure will drop down to about 20 lbs at idle, but pop up to 30 lbs at 1000 rpm. It will do this all day if I never go above 1200 rpms or so. If I take the boat up to cruise at 3200 rpm it will have 40 lbs of oil pressure the entire time I am at 3200 rpm. If I stay at 3200 rpm for 2 minutes or 22 minutes still 40 lbs of pressure, the moment I slow down the oil pressure drops to about 5 psi at 1000 rpm and 0 on the gauge at idle. If I start back up to 3200 rpm it will come back up to 25 lbs, but never to 40 lbs.
If I run to 3200 rpm for 1 minute it does the same thing. I appear to lose all pressure the second I slow down after cruising regardless of how long I cruise, if I shut the motor off and wait an hour I can duplicate the result, whatever the issue is it resets itself after sitting.
Any Ideas?