It is OK for the engine cooling fan to keep running for a few minutes after turning off the car. Your car fan will run for a few minutes after you turn off the car then turn it off. This is normal in many vehicles, such as BMW or Mercedes-Benz. The radiator fan may run up to five minutes and sometimes longer.
When the engine is running, the coolant circulates and flows to the radiator, where heat is dissipated. When the engine is turned off, the coolant doesn't circulate, and the heat stays trapped, therefore prolonging the engine from cooling. Running cooling fans help cool down the engine even after you turn off the car. If your cooling fan runs for over 10 minutes after turning off the engine, you may have a problem that needs to be fixed.