I’m working on a 04 Liberty w/3.7. When the engines cold and running It has 80# of oil pressure at idle. then once it warms up and engine is at 1500rpm the oil pressure drops from 80-0#s in 40 seconds. I have tested w/mechanical guage so #s are accurate. Could this be oil pump problem,spun bearing or as simple as needs a new filter, it now has a fram filter.
check for sludge on oil pump pickup