Why does the oil light comes on seconds after the car is started?

If the oil pressure warning light is coming on after the engine is started, you have a problem. The light is telling you the pressure is low. It may be nothing more than a defective filter or a loose connection at the oil sending unit. It could also be more serious. Change the oil & filter and make sure to use the correct filter. I suggest Purolator, or Wix. If you still have the problem, take it to a professional immediately. Do not drive the vehicle with the light on or you may do serious damage to the engine. I had a problem with the light coming on seconds after starting the car. It remained on for several seconds and went off. It seemed to come on during hard acceleration or hard braking. We took it to a local "import car repair" place and had the pan pulled and boiled, cleaned the oil intake screen, put it back together and we still had the light. After taking it to our nearest BMW dealer we learned it was a faulty oil level indicator. A pretty simple fix... it would be worth checking into before you take on a project yourself.