when you first start the engine up cold, the oil pressure is fine. once the engine reaches temperature, it drops to about 15-20. but once you get above 2k rpm, the pressure is fine again. does anyone else experience this? is it the oil pump giving up or is it the oil pressure sensor? i know that normally when at idle the oil pressure will be slightly lower then when at higher rpm, but should it swing that much? just to let you know the engine has 179k on it.