yanmar alarm, lights v's horn

[stravaig03]

yanmar alarm, lights v\'s horn

I have a yanmar 3GM engine and often (but not always) the audible alarm sounds at 1/2 or 1/4 volume but non of the warning lights are lit. Usually this happens after the engine has been used-say2300rpm- and I reduce to say 1100 on entering a harbour. The warning lights work on test and the audible alarm works at full volume at switch on. I;ve checked the manual but am non the wiser. Any suggestions?

 

[Evadne]

Re: yanmar alarm, lights v\'s horn

Not sure if it is the same thing, but:
On my elderly 1GM I get a sort of rythmic "peeping", with a synchronised flickering of the light if you look closely. I put it down to the oil pressure dropping off when I go from a prolonged run at high revs, which splashes the oil all round the engine, to tickover. The peeping is in time with the engine so could be a crankcase pressure thing. Eventually the "peeping" stops, if on tickover for a while, presumably as the oil drains back down and the mean pressure goes back up. Sometimes I even remember to check the oil level once we've been stopped for a while, but it rarely needs topping up. I guess I ought to check the crankase breather and some of the oilways, which I will do if things get worse.

 

[stravaig03]

Re: yanmar alarm, lights v\'s horn

thanks Dave, I've covered the instruements with a cloth but I've not seen any of the lights flicker. Between entering harbour, reducing revs and shutting off my engine I would guess 10 minutes average. My version of peeping is more of a high pitched 'trilling '-agravating- noise, how long was eventually with your peeping?

 

[Evadne]

Re: yanmar alarm, lights v\'s horn

I would say about 10 or 15 minutes, depending on how hard it was running beforehand. Usually I don't leave the engine in tickover for long, once we're stopped, so it's not easy to tell. I wonder if the "trilling" is because you get 3 compressions (of the crankcase?) per rotation, whereas I only get one?