Abstract: A device for measuring the oil level in the sump of an internal combustion engine. A resistive wire probe extends into the oil contained in the sump. The voltage across the terminals of the probe will vary according to the immersion of the probe in the oil and such voltage is transmitted to a galvanometer in the form of an oil level gauge for indicating the level of the oil to the driver. In order to prevent termination of the signal to the oil level gauge when the engine is started and pumps the oil out of the sump, a timer circuit is provided to continue the signal to the oil level gauge for a predetermined period of time after the ignition switch is closed.