Yanmar 3YM30AE Engine Oil alarm chirping

[Copacabana]

Have you got the part number? I'll see if I can track one down north of you (perhaps Salvador).

[Mike Banks]

The circuit is simplicity itself, an oil pressure switch which operates if the engine oil pressure falls below 0.-1 to 0.03 MPa (1.42 to 4.26 psi) with the main switch in the ON position. The contacts are closed by a spring and the lamp ius illuminated through the lamp to oil pressure switch to ground.

Remove oil pressure sensor. Head to Super-Cheap Auto or any auto spares department--or vehicle wreckers, and find an oil pressure GAUGE, if you can not find an appropriate pressure sensor. That will at least set your mind at rest.


I have the engine service manual before me and it looks like a Denso sensor if that is any help. Part number is not available in workshop manual--go figure.

I just downloaded the entire parts catalogue--and the part number is Reference 6, Level 1, Part number 114250--39450.

Hope this helps.

[masonc]

I've had that on my Yanmar 3GM30F because the insulation on the wiring loom was worn and allowed the wire to short to the engine. Try suspending the loom so it does not touch the engine. Also, disconnect the oil sender and see if it still happens.

[B4A]

Originally Posted by Mike Banks

The circuit is simplicity itself, an oil pressure switch which operates if the engine oil pressure falls below 0.-1 to 0.03 MPa (1.42 to 4.26 psi) with the main switch in the ON position. The contacts are closed by a spring and the lamp ius illuminated through the lamp to oil pressure switch to ground.

Remove oil pressure sensor. Head to Super-Cheap Auto or any auto spares department--or vehicle wreckers, and find an oil pressure GAUGE, if you can not find an appropriate pressure sensor. That will at least set your mind at rest.


I have the engine service manual before me and it looks like a Denso sensor if that is any help. Part number is not available in workshop manual--go figure.

I just downloaded the entire parts catalogue--and the part number is Reference 6, Level 1, Part number 114250--39450.

Hope this helps.

Thanks! Can you please share the link to the parts manual?

[B4A]

I was finally able to do the pressure test. The oil pressure goes from 3.5 bar in idle all the way to 5 bars WOT.

So the culprit is the sensor. Thank you everyone for your previous help!

[a64pilot]

You may want to consider installing a permeant pressure gauge, that way you can see an issue coming, spot trends. The idiot lights and or buzzers by the time they alert it may be too late, damage may already have occurred.
Same with a coolant temp gauge, you can see the beginning of an overheating problem, before it actually overheats.

Leave the existing buzzer of course if you do install gauges, there is almost always additional taps into the oil pressure galley and coolant.