Yanmar 1GM10 Oil Pressure Warning

[haddock60]

My Yanmar 1GM10 oil pressure warning beep takes 10 to 20 seconds before it comes on when I stop the engine. When I start the engine it comes on immediately - as normal). Is this normal (new oil) or is it something I need to check out. If so what might it be? I changed the engine oil as part of Novembers winterisation.

 

[rogerdog]

No problems - I would not worry it does simerlar on other boats I've had.

The stopping alarm delay could be retained oil pressure (was the engine hot) but I've never had a 20s delay with a hot engine.

 

[lw395]

What's actually happening?
There is air in the oil circuit, which is pressurised by the oil pump. When the engine stops this pressure leaks away as the oil plows through bearings etc. When the pressure falls to a pretty low value, then the buzzer sounds.
If your engine is taking longer for the buzzer to sound, I would hazard a guess there is more air in the oil circuit. Possibly the filter hasn't filled yet. Or just maybe the oil level is a bit lower and the pump is picking up air when the boat heels?
I'd check the oil level, but I don't think you have a problem.

 

[Georgio]

My 2GM is doing exactly the same thing following an oil change but I think it it may be down to not running the engine fully up to temperature and the oil still being cooler/thicker than when I normally switch off from hot.

Hope that makes sence.

I'll check the oil level also but it should be fine.

Cheers

 

[Relax]

My warning only comes on occassionally when I stop the engine - I assumed this was just the switch sticking?? /forums/images/graemlins/tongue.gif

Always meant to get the thing out and free it - it son the front anyway.

Anybody else have the same problem??

 

[tyce]

[ QUOTE ]
What's actually happening?
There is air in the oil circuit, which is pressurised by the oil pump. When the engine stops this pressure leaks away as the oil plows through bearings etc. When the pressure falls to a pretty low value, then the buzzer sounds.
If your engine is taking longer for the buzzer to sound, I would hazard a guess there is more air in the oil circuit. Possibly the filter hasn't filled yet. Or just maybe the oil level is a bit lower and the pump is picking up air when the boat heels?
I'd check the oil level, but I don't think you have a problem.

[/ QUOTE ]


What an absolute load of drivel, sorry but you are quite simply wrong.

 

[oldharry]

<<What an absolute load of drivel, sorry but you are quite simply wrong.>>

Wouldnt have put it that way myself, but I agree. Oil pressure usually runs around 40 - 60psi , and returns via the bearings etc that it is intended to lubricate. There is just no way any air can remain in the system once the oil starts circulating. If it did the engine would rapidly fail through lack of lubrication.

A good 'tight' engine will lose oil pressure within 2 - 3 seconds once the oil pump stops at working tempratures, maybe up to 5 seconds if the oil is still cold. A turbo engine rather less.

The alarm is operated by a pressure switch, so if it is not sounding as soon as pressure drops, it will not alert you to a lubrication fault in time to save damage if the oil pressure fails in service for any reason. Some engines will run on with just sump splash lubrication - Briggs and Stratton once ran one of theirs for an hour without lube when testing against one treated with Slick 50 (the treated engine seized first by the way!). But generally you have very little time from the oil warning light showing until serious damage starts to occur, so a 20 second delay in response could be seriously expensive!

 

[TheBoatman]

Sorry but I disagree.

If there was air in the system the warning buzzer would activate faster because air is very compressible and conversely would allow the pressure to drop very fast after the engine is turned off.

What is being described here is an engine that has very little wear on it, a good pump, tight tolerances between the bearings etc. So that when the engine is switched off it takes time for the oil pressure to drop sufficiently for the buzzer to sound.

Peter.

 

[tyce]

[ QUOTE ]
Sorry but I disagree.

If there was air in the system the warning buzzer would activate faster because air is very compressible and conversely would allow the pressure to drop very fast after the engine is turned off.

What is being described here is an engine that has very little wear on it, a good pump, tight tolerances between the bearings etc. So that when the engine is switched off it takes time for the oil pressure to drop sufficiently for the buzzer to sound.

Peter.

[/ QUOTE ]

I agree with you, only other possibility is a duff / incorrectly rated pressure switch.

A quick check that might be worth doing is-
with the ignition key in the on position remove the wire from the sender (located bottom left ) alarm should stop immediately, then touch the wire against the sender terminal and alarm should sound immediately, this will only take a minute to do and will prove all is well with the wiring.