Solving oil pressure fluctuations issue

All,

After 40+ new hours on the engine since the Yanmar "fix" was applied, I am happy to report that our oil pressure fluctuation issues seem to have been resolved. No more alarms, no more precipitous drops in oil pressure when you decrease rpm, no more craziness.

And looky what I got from the internet! I have posted a four page service bulletin from Yanmar in my photo gallery:

gallery2.php?g2_itemId=38756

The bulletin states what it takes to fix this issue. This should be of use to those of you having the problem now and to those of you who WILL have the problem in the future (as the resistance increases on the ground wire to the oil pressure sending device). I hope this helps. Do not despair if your oil pressure goes nuts. It is not the engine.

Jeff

Is this an R-27 4BY2-180 specific issue I wonder ? The bulletin refer this issue to be in the BY series so I assume this also covers the 4BY2-150 Yanmar in R25s, right ?

Pretty sure this applies to all the engines in the BY series. In tracking reports on this website it does not appear to be limited to the 4BY2-180.

This applies to all BY, BY2, and BY3 engines. There are two parts to the advisory, running a new ground wire for the oil pressure sensor and reprogramming the interface unit (firmware update). The new ground solves the erratic oil pressure indications. The firmware update changes the analog to digital conversion so the indicated oil pressure is closer to the actual pressure. At low RPM the indicated pressure will be much higher than before. The update also solves a potential issue with a low pressure alarm upon sudden throttle down.

I plan to run the new ground wire myself and have a Yanmar shop return my interface unit for the firmware update during the winter layup.

Howard

Is this Yanmar service advisory also recommend by Ranger Tugs ?

In the past Andrew has posted a notice sindicating advice for Yanmar engine owners to avail themselves for the free Service Advisoriy updates provided by Yanmar.

It is my understanding that this is a covered warranty issue regardless of how old your engine is.

It is my understanding that this is a covered warranty issue even if your engine is out of warranty.

I contacted my Yanmar engine service company today and gave them the Yanmar Service Advisory for this oil pressure fluctuation issue. They contacted Yanmar for reimbursement authority and were told that Yanmar will only pay for the upgrade modifications if the owner has encountered the oil pressure fluctuation issue. Since I've encountered it on my 4BY2-150 engine this service will not be covered by Yanmar.

So I either lie or keep going until in may happen. 😱 I'll keep going. 🙂

BTW... at this time there's no time limit placed on this modification by Yanmar.

Yanmar has indicated the problem appears to be related to just a few of their 4BY2 engines so far. If was told today that anyone encountering this issue Yanmar will make good on reimbursing the cost of the modifications even if the engine out of warranty.

I just had this problem on our 2013 R27 today with 350 hours. I will be contacting the local dealer on Monday to find out what will/can be done. None the less, I will be installing a mechanical gauge as this is too important to leave up to fluky electronics....

Ken

R27 O'Meara

Sorry to hear this, because it is really annoying when this happens. Still, there is a fix, and I am happy to report that 150 hours since, there have been no issues.

Ken,

I had the "fix" installed - but it took two dealers and neither dealer would file with Yanmar - so I paid about $400 so far.

The first dealer sent the ECM back for a firmware upgrade They charged me about $300 for the "service" and it changed the numbers on the oil pressure gauge - not really necessary since I don't especially care if "normal" operation was 35 psi or 45 psi. That project cost me $300 in service and about $800 in slip fees since I had to take the boat to them.

The second dealer was MUCH NICER. He allowed me to keep the boat in the home slip and rewired the engine as directed in 1/2 hour or so for a cost of $112.

It worked perfectly for 4 hours.

Now I have no oil pressure - in fact, I have no indication the engine is equipped with an oil pressure sensor. The mechanic returned, checked the sensor, all his wiring, and put the engine back as it was - still no pressure.

Now my questions:

1. What sensor did you use? Since the Yanmar engine uses a metric sort of sensor, the usual fix of putting in a sensor suitable for a 67 Ford won't cut it - it just leaks slowly.

2. How did you get the wire forward for the new sensor?

3. Where did you put the gauge - or fault horn?

Thanks much /Stu