Chrysler Repair: oil pressure too low?, gauge reading, pan gasket

Question
I have a 1988 Dodge d-100 pu. When I start the engine cold the oil pressure goes to 50 psi. After the engine warms up the oil pressure drops and the oil light comes on. I have replaced the oil pan gasket,oil pump,and sending unit. they dont seem to fix the problem. It dont smoke or use any oil and the engine runs good under the condition, so I ask what else could be the problem. PLEASE GET BACK TO ME.

Answer
Hi James,
You didn't tell me the rpm conditions under which the 50 psi was read, or after warm up, so I can't make too much ot it. The 50 psi I assume is OK from your point of view. If the oil light comes on at warm idle, then that is not too unusual. I would always be concerned if it came on at rpms over 1,000 rpm. Is you 50 based on a calibrated gauge reading and if so what is the idle warm pressure? If you haven't measured it with a gauge then remove the sender and test it with a calibrated gauge.  The usual idling minimum pressure is 4 to 6 psi, while at 3,000 rpm somewhere between 25 and 80 psi, but again I am not sure what engine is in the pick-up that you own. So consider those possibilities and of doing a reading with a real pressure gauge and compare to the specifications for the engine. Let me know the engine and I can probably tell you the specs.
Roland