SB8 Engine Oil Problem

[jneely]

I started up my Yanmar SB8 engine today and the oil pressure gauge indicated no oil pressure. This happened once before, but the pressure came up to normal in about 30 seconds. Not today. It idled smoothly, but the pressure never came up. The overheat warning light did not come on. I have two questions. First, what might be causing this? And two, did I do any damage running the engine? Thanks for all responses.

[mgphl52]

First thing I would check is for the wire from the sending unit being disconnected. Secondly (which I imagine you already did?) is to check the oil level with the dip stick.

[sgbernd]

Assuming your dipstick shows plenty of oil, and the oil looks like oil (not mayonaise or smelling of diesel) it is unlikely the engine is the problem. Most likely problem will be the sender, wires, gauge, 12V isn't present, etc. I've known one oil pump failure in my life but that was on a new car and infant mortality.

-steve

[Coosaw]

Jneely, Your post reminded me of an oil pressure problem that I had many years ago. My boat had a Westerbeke engine with less than 50 hours on it. Sunday morning in preparation to getting up the anchor, I fired up the diesel and quickly discovered that I had no oil pressure. There was plenty of oil on the dipstick so the only thing to do was to sail back to the dock. Monday morning I was on the phone with Westerbeke. Since the engine was still under warranty they wanted one of their certified mechanics to look at it. After a 150 mile road trip from Savannah to my home port, the mechanic showed up at the dock at the appointed time. He used a manual pressure gauge to confirm that in fact I had no oil pressure. Next he asked to be taken to an auto parts store where he purchase a can of Marvel Mystery Oil. Back at the boat, the Mystery Oil went into the crank case. After a few minutes, he restarted the engine and the oil pressure was back to normal. Seems that the problem was a sticking valve on the pressure relief valve. Problem solved and he admonished me to add the Marvel Mystery Oil to the crank case with each oil change. I did and never had another problem with oil pressure. Not sure this will help you but I have enjoyed the memory.
Rick