Car in question is 2000 V70XC with 40k miles, was gummed up internally due to short mileage driving. Initial oil pressure on start up is 60 psi, declines slowly over time while driving, seems to be driven by engine load. Will decline to zero if allowed, but if ignition is switched off and back on (while driving with tran in neutral, or when stopped), oil pressure will jump back to initial level of 60 psi. All internals have been cleaned of coking, including all lines and vent components. All o-rings and seals in oil system have been replaced, oil pump replaced, variable valve timing piston assy and solenoid replaced, oil filter and housing replaced. Bearing clearences have been checked and are within spec. Oil pickup has been removed several times and checked for obstructions/leaks, new seals installed each time. Oil pan removed and replaced with new o-rings between pan and block replaced each time. Oil pressure sensor has been removed and diagnostics conducted with mechanical oil pressure gage (2 different ones to ensure gage was not culprit). Dealer has no clue, I am out of ideas, need help!

Know of any other components on the pressure side of the oil system that are electronically controlled like the CVVT solenoid?

 

Does your car have a oil cooler?
Did they replace the o-rings in the oil pan?

 

yes and yes. I have done all of the work myself, so I know that all seals and o-rings have been replaced. Oil cooler was removed and flushed.

 

Let me ask around and see if I can come up with anymore info.