BMW E46 oil light on: oil level sensor
E46 yellow oil light comes on at start-up, what is wrong?
The yellow can indicates the oil quantity. If it comes on at every start for about 10-15 seconds, the fault is usually the oil level sensor in the oil pan. It is a typical fault and has nothing to do with how the engine runs.
E46 what is the difference between the yellow and red oil light?
The yellow light indicates low oil quantity or a level sensor fault. The red light means oil pressure and is a real alarm: stop the car and find out the cause.
How do you replace the E46 oil level sensor?
The sensor is on the underside of the oil pan, and it can be replaced during an oil change: undo three nuts and unplug the connector. A good-quality replacement sensor has fixed the fault better than a cheap aftermarket sensor. Still check the oil level on the dipstick.
E46 oil light still on after replacing the sensor, what else could it be?
A leaking oil filler cap seal can trigger the light, and replacing the cap has removed it. The cause of the warning light is worth reading with a fault code reader.