2007 Larson cabrio 240 beeping and in limp mode

[ingham01952]

Quick story.
2007 Larson cabrio 240 with 5.0 gxi Volvo penta.
Fresh water cooled (coolant with heat exchanger)

First day boat was launched in may and before even getting above 10 mph the the dash started beeping 3 times in perfect sequence.

All gauges were fine. Temp good, pressure, oil Checked etc. no issues. Beeps just wouldn’t go away. It’s the same alarm as when you first turn key. But that sound is a quick 2 shorts and a long and then goes away. Mechanic comes down the next day but not able to recreate issue. This issue seems to have vanished and boat was used both easy on river and wide open on ocean without issue.
Now, today I was traveling at about 35 in ocean and when I started to slow down the 3 beeps came back. I had been hammering down for about 20 minutes before that but not full throttle. When the beeps started the engine also went into a limp mode I assume. There’s barely any power. When you try to speed up it sputters like it’s cutting out.

Anyway, just like last time the 3 beeps won’t stop. Temp is at 175, oil pressure 60, voltage 13. Plenty of depth, and fuel is full.

Any ideas?

Engine is not over heated. Manifolds are not hot to touch.

 

[alldodge]

I moved you to VP area, you posted in FAQ area

It's a GXI - what?

Showing 13V with motor running is not good (if your using a hand held meter and not the one on the boat). What is the voltage reading with a hand held meter at the Battery with motor running?

 

[ingham01952]

I’m going off dash voltage

 

[ingham01952]

Update. After about 20 minutes of limping the beeping stopped. After limping for another 20 minutes or so with no beeping decided to shut off and see if it would operate normally. Restarted and ran normally for about five solid minutes of ripping, and then went back to beeping and limp mode

 

[ingham01952]

See dash

 

[ingham01952]

I moved you to VP area, you posted in FAQ area

It's a GXI - what?

Showing 13V with motor running is not good (if your using a hand held meter and not the one on the boat). What is the voltage reading with a hand held meter at the Battery with motor running?

 

[alldodge]

Thanks
5.0GXI-GF and has 555 ECM and HSV distributor

My guess is it's a sensor that lost connection (exhaust temp, water temp, oil pressure, other) but this is just a guess. These new motors need a scanner to tell us what's happening.

If you can get it scanned for codes we would have a better time figuring it out.

 

[ingham01952]

Ok. I will work on that. I was thing oil pressure sensor. Thank you for your input.

 

[Donald0039]

Why didn't the mechanic who could not recreate it scan for codes? Or did he? There could be pending codes or stored codes.

Either get a mechanic with a Diacom or buy one. Need to scan codes from time time.

 

[ingham01952]

update*
That is the alarm. It’s hooked to my voltage gauge

 

[ingham01952]

ok. I have a theory…
I found a small pin hole in the hose going from heat exchanger to the engine. I think maybe the water pump. This is creating a small fine mist that is spraying at high rpm’s. Maybe the terminals got a little wet and it was causing the boat to think there was a voltage issue?

Or maybe I’m overthinking this alarm being hooked to the volt meter?

It’s the same alarm that goes off when you turn the key to let you know you have put power to the boat.

 

[Donald0039]

Well in this case you obviously replace the hose with a high quality but expensive VP hose.

Is the alarm where it is as that's where it gets power from but signal to turn it on comes from elsewhere?

 

[ingham01952]

Well in this case you obviously replace the hose with a high quality but expensive VP hose.

Is the alarm where it is as that's where it gets power from but signal to turn it on comes from elsewhere?

No, the initial start up sound of
“beep beep beeeeeep”
This goes always sounds open turning key on and then stops. This same alarm is also now doing the constant 3 beeps while engine goes into guardian mode.