:smt100In my 2000 410 da I have 2 7.4 mags they both sound and proform well but the starboard engine after it warms up ,the oil pressure slowly drops from 40 to 20. So I changed the oil with 25/40 as recomended by merc. and the oil pressure then stayed at 40 lbs. for the rest of the day wich was only a couple more hours of opperation. Then the next time I used the boat was a week later, the oil pressure was back to dropping to 20 lbs. after warm up. Does any one know whats going on or any ideas???? I have a bad feeling about this, hopeing i'm wrong.
low oil pressure
- Thread starter beachnut
- Start date
- Oct 4, 2006
- 2,344
- Boat Info
- 2006 300DA Sundancer
- Engines
- 350 Mags / Bravo III
After you're warmed up, what is your oil pressure at idle? I suspect that your oil pump has lost its efficency and isn't displacing the volume that it should once the engine gets up to temps....not sure if your style of oil pump has a high pressure bypass built into it or not.
BonBini
New Member
What is your oil pressure at hot low idle and under load at cruising speed?
BonBini
New Member
20psi @ hot low idle.
20psi @ cruise rpm.
You'll now want to test the oil pressure with a live mechanical gauge. Perhaps the thing to do is to buy one from local auto parts store, install it to your engine and just leave it there for future reference.
Sounds odd that the pressure doesn’t come up from hot low idle - cruise rpm. Mechanically this is not the norm. Even with internal problems. Could be a positive sign the current instrumentation is at fault.
Just for reference. What does the port engine do?
20psi @ cruise rpm.
You'll now want to test the oil pressure with a live mechanical gauge. Perhaps the thing to do is to buy one from local auto parts store, install it to your engine and just leave it there for future reference.
Sounds odd that the pressure doesn’t come up from hot low idle - cruise rpm. Mechanically this is not the norm. Even with internal problems. Could be a positive sign the current instrumentation is at fault.
Just for reference. What does the port engine do?
I am going to the lake next weekend and I will install a mechanical guage on the block and hopefully it will show pressure consistant with the port side. I will report my findings as soon as I know something . Thanks again for your imput!!! Gus
beachcombersc
New Member
Any luck???
