Sudden loss of oil pressure

[Michael Buchanan]

I have a 97 Pursuit with twin 370 hp 6bta engines with approximately 1350 hours. I was running it yesterday and slowed to go through the wake of a large motor yacht (intracoastal in Florida). When I went to accelerate I heard a loud pop and lost oil pressure in the port engine. I shut it down and limped home. When at the dock I turned on the electric pump I installed to pressurize the system before I start them and it had its normal 30psi, so the sender and gauge are working. I started it and it idled and sounded normal, but when I shut off the electric pump I have no oil pressure. My question is, is there anything besides a failed oil pump that could cause this? Oil was changed on both engines two weeks ago. Before I pull front cover I wanted to see if there was something I’m not aware of. Thank you.

Topic

[Tony Athens]

Start with a solid installation of a quality liquid filled 0-200 PSI  mechanical oil gauge on a hose whip that you can monitor when running the engine

[Rob Schepis]

“The oil level is full”  What exactly does that mean?  Have you read this: https://www.sbmar.com/articles/oil-pan-capacities-for-cummins-marine-engines/

So what was the “loud pop” you heard?

[Michael Buchanan]

Oil pressure

The oil level is full. I ran it at the dock again a week later and pressure was normal. I don’t think there’s any way for that to happen with a mechanical failure, so I probably lost the reading and not the pressure. Why it came up with the electric pump is a puzzle because it reads off the same sender. As I said, when I got back to the dock after losing pressure I started the engine again and it still showed no pressure.  So I’m pretty confused now, because I don’t know what happened or how it cured itself. I’ll have to run it under load again and see what happens, but that has to wait because I have to reseal one of the greats and I want to get that done first. Always something!

[Bill Desmarais]

Cummins 5.9s are not know to have oil pressure issues.

What was the oil level in the affected engine when you got back to the dock ?  

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