Oil Pressure

[RicM]

All:

I am curious what your oil pressure reads on Yanmar 315's? I have just replaced all my gauges with new Faria gauges. The oil pressure reads about 20 lbs at idle and gets as far as 40 at cruise, though I haven't really run it up yet for any length of time.

[JackK]

Hey Ric -

My stock gauge reads about 20 at idle and around 40-50 at cruise. I had a sending unit go bad and replaced it last season. It used to read a little higher with the older sending unit.

BTW - I panicked when the gauge went to 0. I idled back to port watching for any indication of major problems. I've since learned that there are two sending units. One for the gauge and a second for the alarm. So if the gauge drops and you don't get an alarm too, the problem may be minor and not something to really panic over.

Jack

[Maye Marie]

Rick I am running the same pressure as your engine and have been that way for three years now. It was a concern for me as well. My research with Yanmar, Boat Diesel .com and a few other mechanics and technicians did not produce a definitive answer. Every one gave a large pressure range on the Yanmar engine. I was told numbers as low as 15 lbs. and a high of 75 lbs. as being normal. They all did not seem to pay much attention to the exact pressure as much as looking for a fluctuation. If the gauge starts showing you something other than what it normal reads than you should look into it. Other than that they were not worried about the exact pressure. It makes me a little nervous but three years now and I am still reading the same pressure. All seem to agree that you need to put a mechanical gauge at the engine to know what the oil pressure reading actually is. This suggestion is what I plan on following myself, but have not done so at this point. I plan to use the one on the engine as a base reading to interpret the dash board gauge. I understand you can get a gauge that will screw on to the motor at an auto parts store.

While we are talking about oil, I find that the dip stick to check oil level gives me a few different readings depending on how and when I check for oil level. Does any one know what the best procedure to check the Yanmar engine? If you pull the stick just after running there is no oil on the stick until you put it back in. Always scares me, thinking I have dropped oil. I am accustomed to wiping excess oil off and then sticking for a reading, but not seeing it dry. If you let the engine set and check when cold I will get a higher reading. I am assuming that the dipstick tube has a tight enough seal at the top that the oil once it leaves the tube while running it becomes air locked and will not allow the oil to go back up the tube until you remove the stick. The oil coming from the oil cooler after sitting for a while could be a cause for the higher level after engine cools down. I am thinking the best way is check oil level just after a warm engine run. Pull the stick, wait a minute and then stick the engine. What are your thoughts on this?