intermittent engine alarm

[sjbfish1]

I have a 2004 fuel injected 8 cylinder mercruiser small block. The audio alarm sounds once every minute with 2 beeps. The lower unit oil level is fine, temp, oil pressure fine. It beeps at idle through high speed. I disconnected the lower unit oil resevoir sensor and alarm still beeps. I also jumpered the lower unit oil resevoir sensor and got a slightly different beep along with the original alarm.

Any ideas ?

 

[Don S]

Re: intermittent engine alarm

Assuming you have the 555 ECM (need a SN to know for sure, Merc doesn't go by year on their engines), that alarm is part of the engine gaurdian system.
The 2 bp/min indicates one of the sensors, wiring, fuel injectors wiring, etc. is either open, shorted, or otherwise failed, and it cuts back your power to 90%.
About all you can do is check the wiring, and make sure nothing has come loose.
It needs to be checked with a diagnostic tool to determine what if causing the alarm. Or you get the proper manual for that ECM and check each wire and sensor individually.

 

[hudman]

Re: intermittent engine alarm

If you have smartcraft guages, it will tell you more of what is wrong, i had the same problem ,,, turned out that the oil pressure sensor was unplugged.

 

[sjbfish1]

Re: intermittent engine alarm

I don't have the smart gauge system, oil pressure gauge, temp and i/o resevior all ok.

I think the alarms are driven by independent sendors, I guess is could is be on of them.

The boat seems to run fine although I do not push it to hard, usually 35-3800 rpms.

Thanx for your help.

 

[Don S]

Re: intermittent engine alarm

You have a problem with something, otherwise you wouldn't have the alarm. There are 21 different items that can give you the 2beep/min. alarm. The ECM also limits the engines output to 90%, it doesn't matter if you push it hard or not, and while it may "Seem to run fine" to you does not mean that everything is ok.
Mechanical and electrical things don't heal, but the do get worse. Why not find out what the problem is before things get bad enough that the engine won't run.

 

[hudman]

Re: intermittent engine alarm

Yes Don is telling you straight. Mine ran great, only problem was the occassional beep going off, turned out my oil pressure sensor was unplugged, which i only found after installing the smartcraft tach and speedo,,, not it runs even better. if you are not hitting 42-4300 rpm, then you dont know what the limit on the motor is, mine would cut off at about 4400,
now with it fixed, it will run 4960

 

[Blues Breaker]

Re: intermittent engine alarm

I have a 2001 Mercruiser 496 Mag, standard output, Serial #OM061853 with Bravo II (OM124690) with Smartcraft Tach and Speedo. It is beeping twice per minute and also seems to run fine.

I've recently had a high oil pressure reading, with no alarm of any kind, and mechanic replaced the Oil Pressure Sensor (as opposed to Sender). This seems to have fixed the oil pressure problem.

Now I'm getting the two beeps/minute. The mechanic said the "codes" did not indicate anything wrong.

I've bought and borrowed all the manuals I can find, Mercruiser and Seloc, and poured over the sensors and wiring to no avail. I guess I should get the codes read again.

Can you suggest what I might look for in the ECM code readout?
Do you have any other suggestions?

Thanks

 

[Don S]

Re: intermittent engine alarm

OLD 2006 Thread.

Welcome to iboats Blues Breaker. But it's best to open a new thread when you have a question. Not just tack onto a 2 year old thread with a competely different engine.
In no time, no one will even see your question if more than 2 more replies are received. Most only read the original post.