Gear oil alarm sender

[TexasA&M]

I've got an intermittent alarm (near WOT with a load in the boat) that I believe is coming from the gear oil bottle. The oil level is full and it's fresh, so I don't think it's an actual problem, but I want to figure out what is going on with the alarm.

Anyhow, I need to understand exactly how the sender works. From reading in another post, I believe that it grounds out when the level gets low. This should mean that if I disconnect one of the wires going to the sender, I would disable it. If I do this, and don't get the alarm anymore under the same conditions, that would mean that it's definitely the gear oil alarm that is sounding. Beyond that, I'd need to figure out exactly why it's sounding, but for now I just want to isolate which alarm it is.

Does all of this sound accurate?

Let me know what you think.

- Steve

 

[Presentation]

Your assumption is correct. The low drive fluid alarm is normally open. Unplug one wire and you eliminate that as a possible reason for the alarm.

You need a merc mechanic to plug in a code reader. I don’t think your beeping is from this low drive fluid alarm. Here is a code chart:

 

[TexasA&M]

Excellent info!! Thanks for the chart. I was under the impression that the alarm would only sound for three things; overheating, low oil pressure, and low drive fluid level.

Looking at this chart though, if the drive fluid was low, it would be beeping at me, instead of sounding constantly.

My alarm is constant... Oil pressure is good, and I'm not overheating. I'm actually running very cool (rarely gets to 130). I think the thermostat is stuck open. Do you think this could be causing a low pressure situation where it thinks the impeller isn't pulling in enough water?

The alarm only sounds when I'm at or near WOT, and I start to trim up with a load in the boat. When it's just me and one other person, there is no alarm.

Regarding the scanner, I assume that these engines throw codes just like an automobile.... when the alarm sounds, does it throw a code and then remember it until it has been reset? Where is the port for the Merc scan tool?

 

[Presentation]

....I was under the impression that the alarm would only sound for three things; overheating, low oil pressure, and low drive fluid level....

You missed high bilge water but what you say is true pre-smartcraft circa 2003/2004.

 

[Presentation]

Looking at this chart though, if the drive fluid was low, it would be beeping at me, instead of sounding constantly.

Low drive fluid = steady or constant beep.

I guess give it a try. Unplug one of the wires at the overflow drive fluid bottle and TyRap it off then go for a ride and see what happens.

Please share with us your findings.

 

[Presentation]

Regarding the scanner, I assume that these engines throw codes just like an automobile.... when the alarm sounds, does it throw a code and then remember it until it has been reset? Where is the port for the Merc scan tool?

Some codes = yes, some codes = no memory.

That is one of the reasons why so many people call smartcraft .......well...they call it something else.

You can buy a cheap LED code reader that blinks for pre-smartcraft. Post smartcraft you need the full $400 Rina scan tool then you have it or pay a Merc shop about $100 to do it for you one time.

 

[TexasA&M]

Mine is a 2005 4.3MPI.... does it have smartcraft, even though I don't have the smartcraft gauges?

 

[Presentation]

Mine is a 2005 4.3MPI.... does it have smartcraft, even though I don't have the smartcraft gauges?

If you had the 5.0L, 5.7L or 6.2L I would be positive you would have ‘smart craft gauge capable’ meaning you have smartcarft alarms for the sensors that your engine does have but analog gauges.

I just don’t know the 4.3 V6 as well. I don’t know when they made then switch. I’m sorry.

 

[TexasA&M]

No worries. I'm almost positive that it is smartcraft enabled, but I'll do some other digging around. Either way, I'm going to disconnect one of the wires this weekend and see what happens. If that doesn't do the trick, I think it's time to replace the thermostat.

 

[Henry Boyd]

Mine is a 2005 4.3MPI.... does it have smartcraft, even though I don't have the smartcraft gauges?

This link might help you. It gives the serial number cutoff between Smartcraft capabale MPI engines and non-Smartcraft.

http://www.mercurymarine.com/servic...ntenance/faqs/mercruiser/?category=smartcraft

Henry

 

[TexasA&M]

Looks like my boat is pre-Smartcraft... the serial # starts with 0W0 and the motor was manufactured in Aug '04.

So now that I know it's not Smartcraft, what is the best way to figure out what the alarm is? I'm hoping to get out this weekend and will disconnect the drive oil sender to see if that is the problem. If it is not, what should I try next?

 

[julians]

Did you get to the bottom of this problem?

My boat has just started doing the same thing, ie near WOT with the drive trimmed up, I get a constant beep, and a brief flash on the LCD display of 'pressure'. All the vital signs are good, oil pressure is good, water temp is good. The alarm does not stop until I drop to idle, but then I can throttle up again without issue, until I get to WOT and high trim angles.

I think its either a fault with the water pressure sensor itself, or growth around the water intakes that is blocking flow at high trim angles. There is quite a lot of barnacles around the intakes that I guess could be causing cavitation.

Anyway, my season has now finished, I wont use the boat again until next year, so its going to be lifted and cleaned for the start of the next season, so I guess I'll know if its related to growth next year.

The engine is a 2006 5.0mpi with alpha 1 drive.

 

[TexasA&M]

Never did get to the bottom of it. The problem went almost completely away when I installed my smart tabs, so maybe it does have something to do with the drive angle in relation to the water intake. I will do some more digging this winter when I start doing the regular maintenance.