I have a Yanmar 6LYA-STP in my Mainship 34 RR with about 3000 hour in the engine, new to me as of last year. I did an oil change in the spring and started experiencing high oil pressure readings. The correct oil, filter, and amount of oil in the engine are correct and I used a mechanical gauge to verify the PSI was correct on the helm gauge.
I talked to a number of diesel guys and the Yanmar folks in my area and they all said the pressure relief valve needs to be replaced. I had that work performed by the Yanmar shop (air cooler had to come off so that was Sonic cleaned) and a new pressure relief valve installed. We cranked her over and the engine was still running high.
At operational temp:
Idle- 50 PSI
In gear up to 1600 RPM- 60-65 PSI
2000 RPM- 75 PSI
2400-WOT (3100)- 78 PSI
Yanmar shop tells me that it’s the oil pump and has to pull the engine to drop the pan to access it and I am feeling like that is pretty extreme after the issue started with an oil change. On top of that if the engine comes out you might as well… that list is a long one.
Exhaust and engine temps are normal and I don’t have anything that is leaking oil. I flushed and have changed the oil out (I get the differing opinions on the flush) but am wondering if anyone has either experienced this or has some other areas to look at before I go with the Yanmar shop’s recommendation.
Thanks,
BMur
I talked to a number of diesel guys and the Yanmar folks in my area and they all said the pressure relief valve needs to be replaced. I had that work performed by the Yanmar shop (air cooler had to come off so that was Sonic cleaned) and a new pressure relief valve installed. We cranked her over and the engine was still running high.
At operational temp:
Idle- 50 PSI
In gear up to 1600 RPM- 60-65 PSI
2000 RPM- 75 PSI
2400-WOT (3100)- 78 PSI
Yanmar shop tells me that it’s the oil pump and has to pull the engine to drop the pan to access it and I am feeling like that is pretty extreme after the issue started with an oil change. On top of that if the engine comes out you might as well… that list is a long one.
Exhaust and engine temps are normal and I don’t have anything that is leaking oil. I flushed and have changed the oil out (I get the differing opinions on the flush) but am wondering if anyone has either experienced this or has some other areas to look at before I go with the Yanmar shop’s recommendation.
Thanks,
BMur