5.0 MPI Engine Alarm Sounding

IM Buddy8

Seaman Apprentice
Joined
Sep 23, 2012
Messages
45
I have a 2003 Sea Ray 240 Sundancer with the single Mercruiser 5.0 MPI. Let me start off by saying when it's running, it runs perfect. And that's about 95% of the time. I also did buy a Rinda scan tool and these are the codes that came up (I don't think they are linked to the issue) - Fault Codes 94, 75, 119, 104, 130. I believe they are all linked to sensors the boat doesn't have (ghost codes) but correct me if I'm wrong.

The boat will run fine for hours and roughly every other time I take it out for a trip (usually about a 40 min out and 40 min back trip with the occasional stop to anchor). But randomly I'll be cruising at around 3400-3800RPM's and the engine alarm will sound in the dash (it stays on for about 7 seconds or so when it slows down and I pull the throttle back to neutral). It usually stays running at idle and the alarm is off by the time I'm back to neutral. Sometimes I'll try getting on a plane again and it will do it again in 5 minutes, or it will be fine for another 30 minutes back to the dock.

Also, while it's occurring as far as I can tell it's still got good oil pressure (around 40) and the temp is usually right at 170 where it usually is once warmed up.

I topped off the gear drive fluid, change the fuel/water filter, and replaced one of the batteries with a new one (the issue happens even if I just use the new battery or both).

What could be causing the alarm and as I mentioned it will turn off if I slow down so it's not continuous. If I keep the throttle where it was when cruising and the alarm goes off the RPM's slowly drop and the boat slows down but it does not stall when I'm down to idle.

Any troubleshooting ideas or things I can check with the Rinda Techmate PRO would be greatly appreciated so I can confidently take the boat out with people on it without briefing them on the potential of the alarm sounding and the boat slowing down.

Thanks in advance!
 

Leardriver

Petty Officer 1st Class
Joined
Oct 7, 2008
Messages
380
Drive fluid reservoir sensor failing? Unplug either of the two wires coming off the reservoir while the alarm is going off. If that was the alarm cause, it will go off.
Otherwise, raw water pressure low or engine temp high are the other culprits, in that order, one responsible for the other.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,775
If this is a solid alarm and not a couple beeps then as Leardriver mentioned, I would suspect the water pressure switch on the power steering cooler. But this is not critical fault, and just gives 2 beeps per/m, that is unless your have a MEFI

What is your serial number?
Was it a solid beep?
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
Sounds like a sw pressure alarm but your rinda should show you any faults like this recorded I’d imagine.
Mom aware there are a few different temps for these but my 5.0 mpi runs at 152-158 at the most in any conditions of load or speed. Is it maybe running hot ?
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
I don’t have a rinda, only the vessel view, but can you not run it when the rinda is plugged in and see what’s going on ? I know that temp gauges on the dash can sometimes tell porky pies.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,775
If this is a solid alarm and not a couple beeps then as Leardriver mentioned, I would suspect the water pressure switch on the power steering cooler. But this is not critical fault, and just gives 2 beeps per/m, that is unless your have a MEFI

What is your serial number?
Was it a solid beep?

Need to retract if its a solid alarm then its not the lube bottle
 
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