I have a 1985 Hunter 31 with the original Yanmar 2GM20F diesel engine.
When I recently had the boat out, after about 20 minutes motoring at 1800 rpm, the low oil pressure alarm came on. I promptly shut down the engine, sailed the boat back to the marina, and restarted the engine (no alarm) for about 5 minutes to get back into my slip.
The next day,for the easiest, and first potential "fix" I changed the oil (SAE30) and installed a new oil filter.
I again ran the engine under load, and after about the same time duration and rpm level, and again the low oil pressure alarm came on.
1. The next "fix" I guess will be changing the oil pump. The troubleshooting guide in the Yanmar manual states "see your Yanmar dealer" for oil pressure issues, and the diagrams in the manual are somewhat cryptic as to where it is located.
HAS ANYONE EVER CHANGED THEIR OWN OIL PUMP, AND WHERE IS IT LOCATED ?
2. As the boat (and engine) is 32 years old, I suppose the possibility exists that there are issues with the piston oil rings or the bearings, although I am not seeing any evidence of excessive oil consumption, smoke, loss of compression , difficulty starting, or excessive engine noise or vibration.
What has me most perplexed is that the problem does not occur until about 20 minutes of run time at 1800 (or I presume higher) rpms.
WHAT IS THE ENGINE TRYING TO TELL ME ???
When I recently had the boat out, after about 20 minutes motoring at 1800 rpm, the low oil pressure alarm came on. I promptly shut down the engine, sailed the boat back to the marina, and restarted the engine (no alarm) for about 5 minutes to get back into my slip.
The next day,for the easiest, and first potential "fix" I changed the oil (SAE30) and installed a new oil filter.
I again ran the engine under load, and after about the same time duration and rpm level, and again the low oil pressure alarm came on.
1. The next "fix" I guess will be changing the oil pump. The troubleshooting guide in the Yanmar manual states "see your Yanmar dealer" for oil pressure issues, and the diagrams in the manual are somewhat cryptic as to where it is located.
HAS ANYONE EVER CHANGED THEIR OWN OIL PUMP, AND WHERE IS IT LOCATED ?
2. As the boat (and engine) is 32 years old, I suppose the possibility exists that there are issues with the piston oil rings or the bearings, although I am not seeing any evidence of excessive oil consumption, smoke, loss of compression , difficulty starting, or excessive engine noise or vibration.
What has me most perplexed is that the problem does not occur until about 20 minutes of run time at 1800 (or I presume higher) rpms.
WHAT IS THE ENGINE TRYING TO TELL ME ???