Low Oil Pressure

[Captain Dave]

MY 1990 SUNDANCER W/T4.3 MERC HAS 20psi @ IDLE, COLD IN THE STARBOARD SIDE AND 40psi @ IDLE, COLD IN THE PORT SIDE. VERIFIED WITH A MECHANICAL GUAGE. IS THAT A SIGN OF THING TO COME? WHAT SHOULD I BE SEEING? BOTH ENGINE RUN AND SOUND OK. DOES ANYONE KNOW WHAT THE SPEC IS? :smt100

 

[srt8mag]

Captain Dave,
I'm having the same issue. I'm also seeing a little bit of moisture on the oil fill cap too. I've changed the oil numerous times and the pressure comes up for a little while and then starts falling back down. Let me know if you come up with anything and I'll do the same. Good luck!

 

[JediJD]

Oil pressure is a function of the ability of the oil pump to receive oil (be sure the screen isn't restricted), its ability to pump oil (there are defined tolerances in the pump) and the clearances of the bearings in the crankshaft. All other things being equal, as the crank wears, oil pressure drops. Remember that the oil pump only provides volume, pressure is a function of main bearings. In two otherwise equivalent engines, with equivalent oil viscosities, I would be betting on bearings if one engine is dramatically lower in mechanical oil pressure than the other.

 

[tdappleman]

What are the engine hours? What type of oil and filters are you running?