FA20 Engine Oiling, Bearings, and Starvation

[Eaton PSI]

Engine running! Oil change is about 5.5L with the sump spacer.
Pressure is good with the big pump. When cold its very high, bottoms out the 100psi gauge at about 1500rpm. I have fitted a heat exchanger (WRX, Forester? Not sure...) to help heat the 0w-30 oil quicker.
When hot its about 12-14psi at idle and tops out at about 85psi when spinning fast.

Even with the heat exchanger it takes more than 10mins of gentle driving to get the oil hot. Perhaps this is where bearing damage is occurring. Cold oil, very high pressure, very little flow. The tiny amount of oil in the bearings will get super heated if you push it hard before its properly up to temperature. Also the internal bypass in the filter may open and let sediment and unfiltered oil through your engine.

The water temp is not a good indicator as it heats up much faster than the oil does. The only way to be sure is to get a gauge and monitor the oil temp and/or pressure. Be nice to your engine when its cold and it will probably last much longer.