Lost oil pressure both engines same time

[Mike F]

My neighbor has a 2001 Formula 280 SS with twin Mercruiser 350 Mags (350 hours).

The problem started about a month ago when he lost oil pressure on one engine at high rpm's. He had his mechanic test it with a manual gauge and problem persisted. They changed the oil pump and the problem went away. Following weekend the other engine had the same problem. Replaced the pump in that engine and the problem went away.

Last week he took the boat out and both engines at the same time lost oil pressure. When it happens you will have good pressure then nothing. It doesn't slowly go down just loses it all at once. You turn the engines off and restart them and everything is fine.

Last night the mechanic pulled one of the intakes to look for blockage and found nothing. Any ideas the mechanic is at a loss.

[billinstuart]

1) The oil is too thick and is not draining out of the heads.

2) The oil level is too low.

3) The oil level is too HIGH and the crank is aerating the oil into a froth.

Not much else goes wrong with small block Chevies.

[welder]

Lost the ground wire on your gages.

[v70cat]

Lost the ground wire on your gages.

i was thinking the same thing for both engines to have it happen at the same time seems like the gauges not the engines.

[rchanner]

Lost the ground wire on your gages.

Ditto, or some similar electrical issue.

The likelihood of losing the oil pressure in two engines at precisely the same time is ridiculously low. On the same note: the likelihood that your mechanic is defective and needs to be replaced is much higher. I would suggest that prior to throwing any more oil pumps at the problem, some more troubleshooting is needed.....check wiring, remove oil pressure senders and check the pressure w/ a mechanical gauge, etc.

[ScarabChris]

Yeah something electrical for it to show on both guages. But if he is really unlucky then he could have lost both oil pumps. But like billinstewart said not much goes wrong with small block Chevy's.

When he though he lost oil pressure did any alarms go off? Did the engines get hot? If not then he likely still had oil pressure but wasn't reading it on the guages.

[Mike F]

Yeah something electrical for it to show on both guages. But if he is really unlucky then he could have lost both oil pumps. But like billinstewart said not much goes wrong with small block Chevy's.

When he though he lost oil pressure did any alarms go off? Did the engines get hot? If not then he likely still had oil pressure but wasn't reading it on the guages.

The alarms did go off and apparently they did check with a mechanical gauge when the problem started.

[HOTSPOT]

So Mike, did the mechanical gage verify that in fact there was "low" oil pressure?

[REEL DEAL]

My neighbor has a 2001 Formula 280 SS with twin Mercruiser 350 Mags (350 hours).

The problem started about a month ago when he lost oil pressure on one engine at high rpm's. He had his mechanic test it with a manual gauge and problem persisted. They changed the oil pump and the problem went away. Following weekend the other engine had the same problem. Replaced the pump in that engine and the problem went away.

Last week he took the boat out and both engines at the same time lost oil pressure. When it happens you will have good pressure then nothing. It doesn't slowly go down just loses it all at once. You turn the engines off and restart them and everything is fine.

Last night the mechanic pulled one of the intakes to look for blockage and found nothing. Any ideas the mechanic is at a loss.

[/quote

eather he has the wrong oil pans or the crank scrapers have been left out of the engine and allowing the crankshaft to pick up the oil and spin it around with the crank....very comon in high performance engines

[v70cat]

Have the engines been rebuilt or are they the original from Merc?