2005 f115 oil pressure issue

[Mbremz@gmail.com]

Any news on this issue

Have had the same issue on my f115 for 3 years now.
Sometimes, not always the alarm will go off at start up, gods away If I rev it.
When warm it is fine. Have checked with a mecanical meter, and it goes like this.
Startup - goes straight to 50.
After a few secs - goes down to 20- alarm goes off.
I used a t connection so i could have the oil switch too.

Been this way for atleast 3 years, runns fine. No knocks.

Anyone?

[rodbolt17]

like Boscoe pointed out.
the F115 has a SWITCH open or closed on OR off.
that's is the difference between a SWITCH and a sensor I don't care how it got translated.

a switch is a discrete signal,high or low,on or off.

a sensor implys a VARYING feed back to a con*****ed device or a con*****ing device.

on the F115 it will simply show the switch state,on OR off.

like boscoe I would try a can of crankcase cleaner and a different viscosity of FCw rated oil in the range listed by Yamaha.

could be the oil is simply draining out of the pump and passages after sitting and it takes more than two seconds to make oil pressure in the block.

that F115 system is funky.
at idle BELOW 113*F the oil control activates within 2 seconds of start up.
that F115 ABOVE 113*F wont activate until the engine has been revved ABOVE 2000 RPM.
so if the ECU sees an idle speed and a temp BELOW 113*F it will activate the oil alarm control within 2 seconds.

if you were to restart a hot motor(ABOVE 113*F) at the dock with NO oil in the crankcase and NEVER revved it above 2000 RPM and walked back to the house to get the cool refreshing beverage cooler, the alarm will NOT work,period.

explain that one to me.

but that is how the system works.

[steffenandersen]

I have the same problem with my F115 from 2003.

It is so unfortunate that no one has written what the solution was.
It is a real difficult problem to get solved. I have the whole engine disassembled but can find no fault.

My engine has exactly the same symptom as Hourstonglassic, which started this post
I know that this is a old post, but I am hoping someone has a solution?

[steffenandersen]

I have changed the oil pump and the problem is gone. I think it was the oil pressure relief valve inside the pump. It had some debris in it but not must.

[99yam40]

thanks for posting what fixed yours, I am sure it will help others when they do some searching for this type of problem.
debris in pressure relief valve makes sense for low pressure at low RPM.
higher RPM pumps more oil so relief partially closed would allow the pressure to rise when RPM increased

[Yamayamarin]

Hey !

I had the similar problem With oil pressure on our Yamaha f115 från 2005. We started by testing with the new instruments and controls to rule out that there was something wrong with them. The error persisted after that. The engine was then tested with a new oil pressure sensor to see that there was nothing wrong with it, however, the fault remained even after that so there was nothing wrong with the current oil pressure sensor either.

The engine can sometimes run for 5 minutes before it drops the oil pressure and sometimes for 20 before it warns of low oil pressure and sometimes it does not warn at all. So it drops the oil pressure very irregularly.

The meka****r Said that The next step is to check the oil pump but it is not certain that this is where the fault lies either. There are many different parameters that can come into play when it comes to the engine losing oil pressure some more severe than others.thats why I wonder if someone else Hade the same problem and whats the solution was?

[boscoe99]

Hey !

I had the similar problem With oil pressure on our Yamaha f115 från 2005. We started by testing with the new instruments and controls to rule out that there was something wrong with them. The error persisted after that. The engine was then tested with a new oil pressure sensor to see that there was nothing wrong with it, however, the fault remained even after that so there was nothing wrong with the current oil pressure sensor either.

The engine can sometimes run for 5 minutes before it drops the oil pressure and sometimes for 20 before it warns of low oil pressure and sometimes it does not warn at all. So it drops the oil pressure very irregularly.

The meka****r Said that The next step is to check the oil pump but it is not certain that this is where the fault lies either. There are many different parameters that can come into play when it comes to the engine losing oil pressure some more severe than others.thats why I wonder if someone else Hade the same problem and whats the solution was?

Someone else having the same symptoms as you have may be having a completely different problem. Therefore, their solution will not be your solution. I know that you are looking for an easy trouble shooting method but more times than not it does not work this way. It usually results in folks buying parts they do not need.

Have you installed a mechanical oil pressure gauge to verify that the oil pressure is indeed too low?

How many hours on the motor? What RPM's do you usually cruise at?

[Yamayamarin]

Thanks for your reply! Hope we can get some guidance here as we are stuck in the problem for the last four weeks.
The engine has run 175 hours. We bought the boat earlier this year. In the beginning the children were scared then we drove slowly, about 6-7 knots. Normally we drive around 23-25 knots. I do not really remember but I think that the speed is then at 3,700 rpm. The mechanic explained to us that they have tested the oil pressure but I do not know in what way they have measured it.