My g35 2003 has a problem that when I drive from home to school about 10miles, the cooling fan is turned on while the engine starts. However, when i turn the engine off, the cooling fan is off too.
It's just so short time driving, i don't know why the cooling fan is turned on automatically.
Anyone knows what the problem is ?

 

the cooling fan is turned on with the high speed, so i can hear it when I park the car.

 

not to state the obvious but is your a/c on?

could be that the fan control relay is stuck in the on position.

 

i did not turn the A/C or Heat on.

 

I just noticed it after i changed the coolant flush.

 

did you take out the radiator or remove any connections during the process? Check the electrical connections for the fans. Also the fan relay and the water temp sensor need to be checked.

 

sounds like you might have a bubble in the cooling system. I'd burp the system again.

 

Sounds like you have an 03/04 sedan with the mechanical fan. If that's the case, what you're experiencing is normal. The fluid in the fan clutch mechanism ponds on the lower end of the clutch unit when the car is turned off. When you restart it, the clutch is engaged until fluid disperses. This usually happens within 15 to 20 seconds of the start unless the motor is still scalding hot. In that case, the fan stays on at speeds below 25mph or so. After that, the fan is not engaged because the air flowing across the rad at speed is more than enough to cool the motor.

 

thank you for your help.