Mysterious md2030d engine alarm or squealing sound

[Shaddickp]

I have a Volvo penta md2030d, when I stop and switch off the engine I hear what sounds like an alarm. It sounds for around 5 seconds then fades away. It is definitely not coming from the engine control panel, sounds more like from the alternator or relay maybe. Do these have small alarms? Apart from the alarm the engine starts and runs fine. Recently I have changed the air filter and adjusted the valve clearances but nothing else. Any idea what this alarm ( it may be just a sequel that sounds like an alarm) might be caused by?

 

[tillergirl]

My 2030B used to 'sound' after stopping the engine. It was the alarm function. When the engine stopped, oil pressure stopped and the alarm got triggered for a few seconds.

 

[lustyd]

Yes they are supposed to sound the oil alarm for a few seconds. It should be coming from the panel though!

 

[Shaddickp]

Yes mine does that as well as this new 'alarm'. They emminate from the control panel and stop immediately I switch off the panel electrical supply. This new 'alarm' continues to sound after the electrical supply to the control panel has been switched off, hence I was thinking maybe the alternator.

 

[lustyd]

Hmmm yes that's worrying. I think I'd be looking for blockages where pressure could have built up based on your description as the alternator will stop dead with the engine. In theory it could also be the starter not moving back but that too would stop dead when the engine switches off. It could be the exhause elbow, which is very close to the relays and known for getting blocked so could make a whistling noise.

 

[johnalison]

My 2030B used to 'sound' after stopping the engine. It was the alarm function. When the engine stopped, oil pressure stopped and the alarm got triggered for a few seconds.

Probably not relevant to the OP, but the alarm on my 2030 will sound for a short while after cutting the engine, but only if it has been run for a short time. When it has run for longer this doesn't happen.