What is that loud fan sound when I am running the car and at times when I turn the car off. It sounds like an 18 wheeler.

 

Jagm, I am assuming you are talking about the radiator fans. They may run after the car is turned off for a short period of time. I would say to park the car and the next time you hear it, pop the hood of the car to make sure that is what it is. if they are extremely loud, then it may be possible that one of the blades on the fan have been damaged and it is causing it to be out of balance, which will cause it to run extremely loud.

 

My radiator fans start to make a lot of noise shortly after I stop the car (because no airflow is coming through the radiator anymore due to moving). The noise is actually so loud that I can't hear the exhaust rumble unless I'm standing right behind the car, so maybe I should check the fans too.