[oneilld]

I keep having an intermittent alarm go off after being out on the water for awhile and hitting some rough water. Fluids are fine and I'm monitoring pressure gauges. I've disconnected the alarm feed from the outdrive oil reserve, but still get the alarm from time to time. My Mercruiser shop could not duplicate the conditions. Any way to disconnect the alarm or the other sending units?

[WetWilly]

Hi oneilld and welcome to the club!

I personally wouldn't recommend removing or disabling the alarm system. Should you have an actual problem, you may not notice it until it turned into a very expensive repair bill.

I believe the alarm system is set to sound on the follow conditions, 1) low outdrive oil in the reservoir 2) over heating of the motor and 3) oil pressure loss in the motor.

I would reconnect the oil reservoir wires and move on the the alarm's oil pressure sensor next and if you still get the alarm, move on the the temp sensor. If after eliminating these and you're still getting the alarm, look for a short in the wiring.

Good luck,
WetWilly

[oneilld]

WetWilly,

Thanks for the reply. Will do on the Reservoir sensor. I have a 2008 RS 181 with the 4.3 Mercruiser. The drive oil reservoir is right on top. Where might the engine oil sensor and water temp sensor leads be?

[WetWilly]

Originally Posted by oneilld

Where might the engine oil sensor and water temp sensor leads be?

Hi oneilld, I'll have to look this one up, in the mean time. hopefully one of our members with the same motor will chime in with an answer.

WetWilly

[ShabahZ250]

On my engine, they are Tan wires with a Blue Stripe.

[oneilld]

Thanks,

I can see tan lines with a blue stripe leading out from under the engine block. I'll try to follow them up to a point where they might have a joint. My marina is not full service and so I will have to pull out the boat. I'm trying to postpone to the off season.

[MissouriBoater79]

Onelid,

I am having a VERY similar problem, I posted in the original Mariah forum. I wil let you know if I get any replies, as I am to the point of wanting to throw the sensor overboard.

[Phlorida]

I do realize that the alarm can be annoying but I wouldn't wait until the off season or hope that it goes away. For the most part, I find the Mercruiser alarms to be accurate - you either have low drive lube, low oil pressure or you are over-heating. Any one of those conditions can be catastrophic and that is the reason that they monitor for them. If it is a short, weak connection or something like that you are no longer monitoring the engine for those conditions.

IMHO, the reason for the alarm needs to be rectified whether it is the actual issue or a false warning.

[Petro14]

I just fixed an alarm on my 5.0 MPI, it would beep twice every minute or two and constantly over 3300rpm. I did a google search on it and got slammed with the response of an IAC valve or Idle Air Control Valve. It is a very easy fix, mine was directly under the spark arrestor/air filter. All you need is the correct allen wrench.

Thanks,
John

[SEMIJim]

The water temperature sensor is right up front, atop the engine. You'll see two wires: One on the port side, one on the starboard. The over-temp sensor is the one on the starboard side, if I recall correctly. It'll be a tan wire with a blue stripe.

I don't know where the oil pressure sensor is.

Jim