Hi and thanks for using 2CarPros.com.
Since you mentioned that the noise continued a couple seconds after the engine was off, the first thing I want you to check are the cooling fans. With the engine cold and key out of the ignition, see if you can turn the blades easily and if they make noise.
Here is a general link that discusses the cooling fan:
https://www.2carpros.com/articles/how-an-electric-cooling-fan-works
Next, if the fans are fine, next you will need to remove the serpentine belt and check all belt driven accessories (alternator, power steering pump, water pump). Check to see if any have excessive play in the pulley and spin them to make sure they spin easily and make no noise.
Do this and let me know what you find.
You mentioned the sound was when driving, and then you shut the car, restarted it and everything was fine until you placed it in gear and allowed it to move. After that you mentioned it continued for a couple seconds when the engine was off. That is what I am basing these test on. If it continued when the engine was off, my first suspect is a bad cooling fan motor or the blade is hitting something.
Take care,
Joe
SPONSORED LINKS
Monday, September 24th, 2018 AT 5:09 PM