Oil sensor mounting structure

Of a sensing part (14) and a mounting part (13) of an oil level sensor (12) mounted to a sensor mounting opening (11d) at a bottom portion of an oil pan (11) of an engine, an undersurface of the mounting part (13) exposed to the outside of the oil pan (11) is located above the lowest part (11b) of the oil pan (11) by a distance (±), and the mounting part (13) is disposed in a recessed part (11j) formed on an undersurface of the oil pan (11) and is covered with a cover plate (17). Therefore, the weight of the engine does not directly act on the mounting part (13) of the oil level sensor (12) when the engine is directly placed on a floor surface. Further, even in a state in which the engine is mounted on a vehicle body, the mounting part (13) of the oil level sensor (12) can be also effectively protected at the time of colliding with a flying stone, riding on a curbstone, jacking up or the like. Furthermore, an oil release groove (11i) extending from the sensor mounting opening (11d) to the lowest part (11b) of the bottom portion of oil pan (11) is fomed in an upper surface of the bottom portion of the oil pan (11). This reduces the risk of oil accumulation at the sensor mounting opening (11d) when oil is drained out the oil pan (11).