Oil pressure on 2000 s10
From a cold start oil pressure is at 20,
goes up to 40 at higher rpms, after 10-
15 miles it drops to nothing. I have
replaced the oil pump, pressure
sensor, flushed the engine, had the
screen on the pickup tube cleaned,
gone from 5w30 to 10w30 ... I’m out
of options
What do I do from here?