BMW E30 oil light on - level sensor and pressure sensor
What is the difference between the check control oil light and the cluster oil pressure light?
The check control light indicates low oil level. The oil light in the instrument cluster indicates oil pressure. The oil level sensor measures only the height of the oil level, not pressure.
The oil level light comes on when warm even though there is enough oil. What is wrong?
The level sensor may be faulty or its connector dirty, so contact is lost as the engine warms up. Replacing the sensor fixes the fault. On the M20 the sensor is on top of the oil pan, on the opposite side from the exhaust manifold. The light may also stay on after topping up the oil and go out only after 10-20 starts.
What does the oil pressure light flashing at idle mean?
It can mean low oil pressure and a worn oil pump, so measure the pressure first with a separate gauge. The cause can also be a loose connector on the pressure sensor. On the M20 the pressure sensor is on the exhaust side at the bottom edge of the block, almost under the oil filter.