yanmar oil pressure alarm

[jedjr]

I have an 18 horse yanmar on my hunter 28.Its a 1993 and the model is
2GM20F.Lately when I go to neutral at idle speed the oil pressure alarm
goes off.If I raise the rpms to a 1000 it goes away.It never sounds at any
other time.Ive checked the oil level.It seems fine.Thoughts?

 

[Johnb]

Take it seriously, this does not happen if everything is right and it should be checked and corrected before it deteriorates further and wrecks the engine. With a bit of luck it might be something easliy corrected.

 

[wufibugs]

I agree with John. Could be as simple as a faulty sender or worse from there.

 

[J Page]

Ask the same question to the forum at Torresen's

Brian and fellow guru's can prob. help you pinpoint it.

www.Torresen.com


Pray for Wind,

Lugeman

 

[kloudie1]

Could be a lot of things but start with the easy ones and work through those first..First really is to get a gauge and measure the pressure when idling, the specified pressure is 7 PSIG at 850 rpm.. The switch alarms at 1.4 to 4.3 PSIG.. Bad pressure switch??; plugged oil filter.. changed recently?; Diesel in the lube oil.. ?? oil level going up slowly? (bad lift pump diaphragm); Loose rocker arm mounting bolts?; Dirt/object in lube oil pressure control valve (the part that the filter screws on to) ... Then it starts getting harder.. bad oil pump, bad bearings, either the rod bearings or the main bearings or both.. ..
How many hours on the engine??

 

[Rich M]

Are you using a yanmar filter? Just finished the Mack Boring class and they indicate THERE IS A DIFFERENCE and the $$ is worth it. Obviously just a suggestion and something to look at if you are not using the spec'd filter.

 

[petersea]

What is the idle speed now ?? you said it does not do it at 1000 rpm, the idle should be 750 to 900 already so you are not really raising it that much Could it be set to low ??

 

[Steve Dion]

I had one of the wire connections come loose from the sending unit. They were just glued on. Check this out before you go any further.

 

[Don12364]

Sounds more like the "Alternator Not Charging" alarm to me.
Alternator just needs a new carbon brush for a few cents.

 

[Benny]

Check the grade of the oil being utilized. A 17 year old engine may require a thicker oil than it used when it was new. We have the same engine but a 2000 model and we use multigrade 20-40W in ours. Oil pressure varies with engine rpm, temperature and oil thickness. If the oil grade is too thin or the oil has lost viscocity the oil pressure will drop especially at very low rpm when hot after running for a while. This is just one possibility but I urge you to pursue a solution until the problem is identified and corrected.

 

[jedjr]

Thanks to all of you for the suggestions.I ended up attaching an external oil pressure
guage and found that it was not the problem.Whew.I have ordered a new transducer
to see if it is faulty.I'll bet tha is the culprit.

 

[Alice A.]

We had the exact problem last year and it was a faulty oil pressure sending unit.

 

[kloudie1]

That is good news, Jed.. Check the lead wire to the alarm sender all the way back to the panel. a short to ground anywhere in the wire will trigger that alarm..

 

[Dan Johnson]

Rich M...

don't overlook the fact that Mack Boring sells those "factory" filters. Many of us use aftermarket ones -- Fram's, NAPA's, others. If they can't explain what "difference" makes their filters costs so much more, put down the Kool Aid and go shopping. Filter makers don't make products that don't comply with engineering specs and designed to fail. Others on this forum swear by the factory ones so the choice is yours.

 

[Rich M]

Dan:

The apparent difference is the Yanmar filter contains a bypass if the filter itself gets so filthy nothing flows through. I am not saying others don't have that, but for my peace of mind I'll spend the extra buck or two and enjoy my sailing. I don't trust the parts jockeys that just might provide something that screws on and "fits".

As I said, just something to be aware of.

 

[wufibugs]

Peace of mind is certainly worth something. All oil filters have a bypass spring for the reason Rich noted. Ford suggests using a Motorcraft filter, and while a new Ford Hyundai motor might cost a good deal less to rebuild than my Yanmar, we're still talking way better than a grand. Despite that, few of us have a problem with Fram, etc. I suppose it comes down to whether there is any substantial reason to believe that the specs Yanmar demands of its supplier substantially exceed what, say, MB demands from theirs [lots of Benz owners using aftermarket filters]. Don't most of the aftermarket filter makers supply filters for diesel truck engines?

 

[Dan Johnson]

RichM...

Wulfibugs summed it up.

I'd say shame on the owner that let his oil get so filthy that it clogged the filter and activated the filter by-pass. The filter is hardly the problem then.

Those of us who do regular maintenance after so many hours or at season end by changing oil and filter will not likely suffer that problem.

 

[Rich M]

No real argument

I could not agree more, I simply repeated what had been recently shared at a Yanmar class. I for one prefer to "over maintain" my boat, especially the engine because I just can't afford a new one and really enjoy my time on the water.

Let's go sailing!!