I have a small leak ont he camshaft which was advised it wasn't too urgent to get fixed just do it in the next few months or so. Then today driving home the oil light came on, when i checked the oil it was up at the third notch which makes me think its fine? Does anyone know how low it has to get before it triggers the light to come on? Don't want to fork out the money on topping up the oil if its just the sensor?