Oil pressure 20-25 at idle drops to 0-5 at idle once it warms up. oil sensor replaced, no help - Ideas? Thanks

77 GM 350 - approx 80,000 miles on motor. It is in a 67 El Camino. Motor runs strong, no internal noises. I replaced the oil sending unit and no improvement. Oil in the motor is 10W30. Next oil change I am going to use 10W40.Oil pressure 20-25 at idle drops to 0-5 at idle once it warms up. oil sensor replaced, no help - Ideas? Thanks
Remove the sender %26amp; install a mechanical sender. Don't install the gage. Attach the line to the gage %26amp; start the engine. The reading may be different from the electric gage.





禄禄禄Oil pressure 20-25 at idle drops to 0-5 at idle once it warms up. oil sensor replaced, no help - Ideas? Thanks
could be the oil pump my brothers truck dose the same thing it has no pressure at idle but it goes to 10-20 when you get on it. its been doing this for about a yr and no noise from the engine, and it still runs strong. try adding lucas oil stablizer to it and that might work, you could get a mechanical pressure sensor that way you know if it has pressure or not. good luck
i would say the oil pump is weak.
try differnt gauge and only 80K in 30 years...may be bad oil pump..when if ever rebuilt...did it sit for long periods