I dont know how to fix this so any help would be awesome... It is like that when the car is on or off.

 

gauge is bad. see if you can find someone that works on that sort of thing. the motor on the back of the gauge has gone bad. most of the time gauge places have a price to do all the gauges. but you can call around.
good luck.

 

There is also a very small possibility that the needle just came loose and slid down.

 

If your handy with a soldering iron you can rebuild it yourself. You can get the stepper motors in a kit form on ebay with the newer upgraded motors and new illumination bulbs for @ $30.

 

check the connections to the temp sensor first. a bad ground can do this too. Ive had it happen a few times.

 

Mine has done that when I diconnect the battery, after driving it a bit it fixes itself