Need help oil pressur issue

[Mathieu Roy]

Hi guys hope you're all doing well

Here my issue

I got the boat at the beginning of the summer everything was working well

It starts about two weeks ago it was only when I was Going more then 21 mph and drop the speed 0 ( wakeborading)

When someone was falling and I was dropping the speed quickly to 0 the pressure gauge was slowly dropping to zero and the lights on the dashboard was starting to blink low-pressure issue

Now even if I go around 9 mph and drop the speed 0 it does the same problem all the time

The boat is a super air nautique team 2003 with a pcm 330 the gray engine cap
the boat have 395 hours to oil level is good


Any one have a idea what can be the problem or anyone as experience this problem before


Thank you guys

[ScooterMcgavin]

Oil pressure sending unit possibly going bad?

[t.franscioni]

When you say "drop the speed to zero" do you mean you are pulling the throttle all the way back into neutral?

how long does the low pressure oil warning stay on after going to 0 as you say?

What makes the warning go away? Are you turning off the boat, giving it throttle, or does it just go away on its own?

[t.franscioni]

In addition, can you confirm that BOTH your oil pressure guage goes to zero and your oil pressure warning comes on? On the GT 40 these guage and warning indicator are two separate systems so if one indicates low pressure and the other does not then it likely means a faulty sensor but if both indicate the same condition then you can figure that maybe there is in fact a low pressure condition. Not sure if 330 is set up same way?

[Mathieu Roy]

Thanks for the reply

What I meant about dropping to speed to 0 it's to put the throttle back to neutral, the oil pressure will decrease slowly through zero.
if I give a little bit of throttle before it go to zero everything going to be good ,but if I let him sit at the Nautral it will go through zero and the low pressure warning will come up

After a couple seconds if I let the throttle at the neutral position oil pressure will come up by myself after maybe 15 seconds but sometimes I need to increase the truck a little bit to bring the oil pressure back up.

[t.franscioni]

And how about when you just start your boat and let it idle in neutral? Does the pressure go to zero at all just during a normal idle after start?

[Mathieu Roy]

It will run good !!!
the problem only happen when it decrease from a higher speed to neutral

[t.franscioni]

Ok so..... I have no idea what's causing this intermittent oil press loss.

Thinking out loud,

sticking oil pressure relief valve. As rpm increases oil pressure climbs until the relief valve activates holding it to say 80 psi or whatever, then you pull throttle back and relief valve should close as rpm decreases, well maybe it's sticking and closing irregularly allowing a bypass of too much oil as rpm and subsequently oil pump rpm decrease resulting in zero oil pressure until the relief valve finally does close after as you say 15 seconds or do...??? Test this by revving engine in neutral up to say 2200 rpm hold it there for a second then come back to neutral and see if it does it then. If it doesn't then it has something to do with actually bring in drive.

[Mathieu Roy]

Bring in drive ???

[t.franscioni]

I'm saying if you get don't get this low oil pressure condition if you rev up in neutral then it may have something to do with the prop turning and going to idle from a state of forward motion.... I'm just trying to help isolate under what conditions you get this low oil pressure condition so a fellow member here may better help us figure out what's wrong with your boat. So far we have faulty sensor and what I'm suggesting a faulty oil pressure relief valve. Might be something else too I just don't know what else it could be.

[t.franscioni]

Oops sorry I meant to say "being in drive"

[Mathieu Roy]

It cannot be a faulty gauge ?

[t.franscioni]

Yes it can. That's a possibility. I just saw that someone already posted that advice so I'm trying to help offer alternative answers for you. But if it's like my GT40 motor the oil pressure guage and the warning indicator are both two separate systems so the fact that both the guage and the oil pressure warning both indicate low pressure then both would have to be faulty and the odds for that are stacked against you. Doesn't mean it can't happen but it would be rare. Again if they are both separate systems on the Chevy which I don't know I'm just assuming.

[ShouldbeWorking]

Hook up an oil pressure gauge to the motor and run the motor. That will tell you if the gauges are accurately reading the pressure loss or not. If the oil pressure gauge matches the boat gauges, then you have an oil pressure problem. If the oil pressure gauges do not match the boat gauges, then you have a gauge problem.

[Darrenm55]

I have exact same issue you figure it out