My 2005 Chrysler 300 leaks oil and oil light comes on when car idles. What's the problem?

Chances are the leak is from the oil sending unit and its being bad is causing the light to come on. Check that first. NOTE: I am assuming that you don't hear any ticking or knocking when the light comes on.

--Check the oil pressure with a gauge if normal replace oil pressure switch if abnormal could mean oil pump or engine bearings