Yanmar 3YM30AE Engine Oil alarm chirping

[B4A]

The Engine Oil alarm on my Yanmar #YM30AE with 223 hours started to chirp when revving more than 2,100 RPM (only when in gear).

Needless to say I have replaced engine oil and engine oil filter and cleaned the contacts on the engine sensor.

What else can I do to try to fix the problem?

[Compass790]

Not being familiar with that model engine i'll make some general suggestions. Most likely problem is the sender . I guess you don't have a seperate oil pressure gauge. If the sender has a 1/8" or 1/4"NPT fitting I'd be tempted to put a tee in & have both a mechanical gauge & the oil pressure sender reading out of the same gallery if possible. I wouldn't be without an oil pressure gauge myself. The alarms fail a bit
Unusual for the alarm to go off at highish revs so unlikely to be a pressure problem but good to check

[B4A]

Thanks,

I don't have a separate pressure gauge. Where I am there are no Yanmar mechanics and I don't have access to sophisticated tools.

[Compass790]

Originally Posted by B4A

Thanks,

I don't have a separate pressure gauge. Where I am there are no Yanmar mechanics and I don't have access to sophisticated tools.

Ok you only need a wrench to unscrew & re-install the oil pressure sender & then what A64 pilot says in thread about brown streak on 3ym30ae re getting a gauge.
Assuming there is an auto parts store somewhere near you.
Should be replaced under warranty with your low hours but i hear you about no Yammer mechs there

[B4A]

Are you suggesting to just unscrew, take a look and reinstall the sender?

No auto parts shops where I am...

[Compass790]

No. I'm suggesting unscrew & replace with a cheap mechanical gauge to check what your oil pressure actually is at the revs that you have a problem at.
If there are no auto shops are there any diesel mechanics? They might have one you could hire.
this is the sort of thing I mean: https://www.ebay.com/itm/Sunpro-2-Me...YAAOSwm5xcB0h5

Wierd that it only does it in gear. Does it only do it when the engine is hot?
You have a cat right? I assume you have 2 of those engines so you could try swapping their senders/sensors over & see what happens.
If the problem shifts from one engine to another you have proved the problem lies in the sensor. If it doesn't I wouldn't run the problem engine until you can investigate the actual oil pressure.
hope that helps

[BruceS]

Does it also monitor oil temperature?
In gear & at revs might indicate oil temperature rising?
Kinked oil line to heat exchanger?

[Bawlmer]

I have the same problem with my Westerbeke W20B. The OP alarm chirps like a cricket at 2000+ RPMs. It is electrical. I got it to stop temporarily by replacing the connectors to the sensor. It came back. I solved it again by tightening the connections to the OP sensor until on of the tabs broke and I had to replace the sensor. I got used to the problem. These are electric pulses that are tripping the OP warning sonalert buzzer. Maybe a capacitor installed between the two wires to absorb these pulses will solve the problem. Someday when I have enough time I may figure it out. If you figure it out before me please share.

[Compass790]

Originally Posted by BruceS

Does it also monitor oil temperature?
In gear & at revs might indicate oil temperature rising?
Kinked oil line to heat exchanger?

Yep that's what i was wondering too. The oil pressure will drop if the oil gets hot but you would think it would show up in coolant temp???
Bit of a scary problem on a near new engine.

[lelolay]

Replace the Buzzer. 3YM30AE New engine. Digital control box. Out in the woods...use less until you can get parts. Keep sailing.

[Bean Counter]

IS the OP's boat a catamaran with two engines? If so wouldn't you just swap the sensors to see if it was in fact the sensor?

[Mike Banks]

Replace the engine oil pressure sender--and if that does not fix it you really do have a problem.

If the engine has nor run for too many hundreds of hours you may have a clogged fuel filer or oil pick-up. Oil pressure should increase with engine RPM--and that makes me think it is either not getting sufficient oil into the pump, or the sender is faulty.

You might also make sure you have the right grade of detergent diesel oil in the engine. Yanmar sell their own branded oil. I think it is worth using it..

[Copacabana]

Originally Posted by B4A

Thanks,

I don't have a separate pressure gauge. Where I am there are no Yanmar mechanics and I don't have access to sophisticated tools.

B4A, there are a couple of Yanmar authorized service centers along your route up the coast of Brazil. Where are you now (or where will you be next)?

[rhodemon]

A piece of duct tape over the buzzer will work wonders! Just kidding....The alarm circuit monitors three items: oil pressure, water temp, and alt output. I suspect the problem lies in the charging circuit, disconnect the wires to the other oil and water sending units to confirm this. (both of those senders function by completing the ground circuit so make sure the wires don't touch the engine when doing this because they will cause the alarm to buzz, give it a try so you understand the circuitry, no harm done) Next I would check all of the grounds in the charging circuit, you may have a bad connection somewhere.

[B4A]

Originally Posted by Copacabana

B4A, there are a couple of Yanmar authorized service centers along your route up the coast of Brazil. Where are you now (or where will you be next)?

I'm in Victoria, waiting for the next weather window to sail up to Abrolhos... Contacted a supposedly Yanmar service guy, told me he needs 10 days for getting a spare sensor...