An engine includes: a cylinder block in which a cooling water passage is formed; an oil cooler accommodated in an accommodation part provided in the cooling water passage and having a plurality of cores for cooling an engine oil; a first oil pipe and a second oil pipe configured to support an oil inflow port and an oil ejection port of each of the cores; a cooling water inflow port provided in a lower portion of one end portion of the accommodation part relative to a front-and-rear direction; a cooling water outflow port provided in an upper portion of the accommodation part; and a cooling water inflow passage having an inclined portion inclined downward and connecting to the cooling water inflow port.