Mystery Buzzer/Alarm

[RyanB]

Can anyone help me identify this noise?  It has been to the dealer twice, and they can't replicate it.

Over our July 4th vacation, it went off every time we surfed.  We always had between 5 - 9 people in the boat.  Full ballast.  It is not the ballast pump or the bilge pump.  Water temp is normal. Volts and oil pressure normal.  Oil level is fine.

I can only hear the alarm when I am at or just above idle.  As the RPMs go up, I no longer hear it (although I don't know if it goes away, or if I just can't hear it over the engine/wind noise).

I took it to the dealer, they flashed the computer, and lake tested it and could not replicate.

The noise went away for the next trip.

Last week on vacation it came back, but not all the time.  Once again, only when surfing, but it did not happen 100% of the time.

Thoughts?

 

Another photo of the general settings when it happens.

 

[shawndoggy]

ryan, dumb question, but is it actually electronic?  On my laptop speakers it almost sounds like an air sound, like maybe even a squeak out of your ballast tank vacuum breaker?

[RyanB]

@shawndoggy I'll answer your dumb question with other.  What is a ballast tank vacuum breaker?

I think the sound is coming from under the helm.  But not 100% sure.

Edited August 25, 2018 by RyanB

[wdr]

It sounds like air purging from a tank. I believe he is referring to the anti siphon valve for the center tank. Mine is hung on the bulkhead behind my sub.

[wdr]

This is one.

[shawndoggy]

yeah what @wdr said.  There is one of those vacuum breakers under the helm.

[RyanB]

So how do I find it?

This is the first time in 400+ hours that it started making the noise. 

1 hour ago, wdr said:

It sounds like air purging from a tank. I believe he is referring to the anti siphon valve for the center tank. Mine is hung on the bulkhead behind my sub.

 

[RyanB]

How do I find it as in do I need to remove that panel the sub is on?  Do you think the valve needs replaced?

[wdr]

You might be able to reach over and around the sub box to unscrew the top of the vent to check the valve or tighten the cap down which might stop the noise. There is a rubber duck bill vent in the top of the vent that bleeds air. The duck bill faces down in the vent if you pull it out. I have never been lucky enough to access anything easily on mine.