oil pressure gauge

[Cturtle]

Im running two 350 gas mercruisers. my port engine oil pressure reads 55-60 but my starboard was reading 80. I changed the oil sending unit for dual station and the garage stills reads 75-80. No obvious oil leaks, nuts are all tight on oil pan etc., any suggestions?

[Tony Meola]

Is it possible the gauge is off?

If you can find a mechanical gauge hook it up and double check the pressure that way.

[White Bear]

Swap wires from senders to gauges between the two engines to see if mismatched readings follow. This should indicate if the problem is electrical or if you should go further and install a mechanical pressure gauge. Dual gauge senders often read differently than the single gauge units.

[Rawleigh]

I always tee in a small mechanical gauge at the engine for the peace of mind of knowing what is really going on. In my experience electric gauges never read the same side to side. If the mechanicals show the pressure is good, just keep in mid what the electrics say for each side and notice any changes.

[Carl]

I always tee in a small mechanical gauge at the engine for the peace of mind of knowing what is really going on. In my experience electric gauges never read the same side to side. If the mechanicals show the pressure is good, just keep in mid what the electrics say for each side and notice any changes.

Ditto what Rawleigh said.

Did that motor always read high? Is it a rebuilt motor??

Reason I ask is that my ol 440's had high volume pumps put in when redone, my oil pressure would peg the needle with the standard oil gauge sending unit. I had to buy a different one that skewed the reading. As Rawleigh said a mechanical gauge plumbed in gave me a true reading.