6BTA 5.9 Oil Pressure Loss

[pete-4394]

1998 Carver twin 6BTA 5.9 370HP port engine serial number 45500671. After oil change in both engines the port engine loses oil pressure with increase in RPMs. After warm up to 180 deg and running up to 1500 RPM the oil pressure gauge on bridge reads normal 55 PSI. Increase to 2500 RPM gauge drops to 0 PSI. No oil under engines and no loss of oil on dipstick. Temps taken with infrared thermometer and bridge gauges do not show any overheating.

Attached pictures show oil sensor/sender? One is on top of oil filter and the other is on side of engine. The pictures is Tony’s Tips show the sender on side of engine has two wires, this one has one, but another wire is hanging there and not attached.

We have been operating the boat since January for 6000 miles (Great Loop). No other issues with oil pressure and have done multiple oil changes along the way. Not really in a position to assemble a mechanical gauge.

Question is – should I be concerned or is it most likely the sensor? If I need to replace the sensor should I get a one lead or two lead sensor?

Topic

[J Dragon]

I’m not Tony by any means but I’ve read enough and observed enough to say:

– these engines almost never have oil pressure issues

– it’s most likely your sender or gauge, and it sounds like someone monkeyed with your sender (no pics tho…post em)

– if you were truly losing pressure the motor would have detonated by now 6000 miles later — how worried could you be haha

– if you can boat the great loop you can get someone to make you a mechanical pressure gauge with hydraulic hose bushed down to a 1/8 npt fitting … with that, confirming your real pressure at the filter head is 30 minutes and peace of mind

– replace the sender from there if you confirm it’s faulty (betting it is)

[Tony Athens]

Pictures ???

[Author]

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