I'm running Merc HP 500 remote oil filter blocks and stock thermostats (220*). Oil temp in one motor is running hot over 4200 R.P.M.

Oil pressure at hot idle is also significantly higher than the unaffected engine. I think I might have an oil thermostat stuck in closed or partially open position, bypassing the cooler.

I haven't had opportunity to feel the cooler to see if it is getting warm, but just wondering ...

I know oil pressure is generally lower when hot, but would bypassing the oil cooler cause oil pressure to be higher at idle?

Can I pull the oil thermostat out and run without it to diagnose or see if it corrects the problem?