Until we know different, lets assume there's a slow external oil leak. There will be no problem driving the car as long as the oil level doesn't get real low. (By the way, there is no "full" and "add" mark on the dipstick. There's now a "Min" and "Max" mark). There's no problem as long as the level is above the "Min" mark, and even a little bit below that is not cause for worry.
When the leak is this slow, the best way to find it is to add a small bottle of dark purple dye to the oil, then search a day later with a black light. The dye will show up as a bright yellow stain that you can follow back to the source. Auto parts stores will have the dye, and those that rent or borrow tools should have a black light.
Sep 15, 2015 at 5:54 PM
