About 1 mile from home I notice the low oil light. I also notice that I have 0 oil pressure at idle but 3+ at around 1500 rpm. Car usually takes a quart between OC. I add 1 quart and that brings it up to 1/2 quart low. Start it and still 0 pressure at idle and 3+ with just gunning it a little. I go for a short drive and still 0 pressure at idle. I'm thinking (hoping) something happened to the level sending unit or the oil pressure switch. Any thoughts?