[turboICE]

Sensor location should be considered as a possible culprit, especially if after the cooler before returning to the engine. I run a fairly large oil cooler on my 06 in front of the radiator, with a free flow filter block and the stock oil heater removed and never have a problem getting and staying at operating temperature. My temp sensor is in a galley plug on top of the block behind the intake. Just replace the blank solid plug with the same plug used for oil pressure on the top front of the block.

 

[turboICE]

Yeah pan is best for temp; what's going INTO the engine.

When you have an oil cooler, the pan is not the temp of the oil going into the engine. For my purposes I want to know the temperature of the oil in its operating environment, where I need the lubrication. #27 on the back of the block for me.

If Subaru wants to read oil pressure from #25, then I do as well. It is low at hot idle, but if it is not immediately responsive to even the slightest throttle you know you have a pressure issue downstream of it.