i have a 2000 dodge neon that some one gave me....i drove it for the 1st time since i got it home and after a few miles the engine oil light came on....and i noticed when i cut it off and then back on again it would go off for a period of time and then come back on (it comes back on quicker the 2nd time). I thought it could be sending unit or needs oil change/ filter/pickup clofgged, etc. i removed pressure switch and installed pressure tester/guage... when i started it up it was reading around 25 psi idle and slightly higher driving...when it warmed up the pressure seemed to drop but still stayed slightly over 25 psi when driving....then it dropped down to 0...again when i turned off the car and turned it back on again the pressure would jump back up for a while....any idae what could be causing this? could this be an electrical problem...i did have some rodents under the hood over the winter and they ate some hoses that i replaced, but didnt see any other wire chewing to speak of...any ideas as to where to look next? if it is oil pump..why is it still working after start up?

 

i don't know anything about neons, but it sounds like something is stopping up under pressure - either the oil pump pickup screen, or an oil galley, or maybe the oil filter is collapsing.

i'd start with an oil and filter change.
if that doesn't help i might try a flush product, like Gunk brand engine flush, or a quart of auto transmission fluid. follow directions exactly.
if that didn't help, i'd see about dropping the pan and cleaning or replacing the pickup screen. while i was that deep, i might just replace the oil pump. i don't know anything about neons, so i don't know if thats an easy job or a hard job.

oil pumps don't really wear out much, and if they do, then they should act consistently. you're problem sounds like it starts up ok, and then sucks in a blockage. then when you shut off the engine, the blockage falls out.