After I flushed my radiator out with that flush kit, the temp gauge needle will start to rise after idling after about 5 min, but driving it'll go back down. It's topped off at the radiator.

probably a dumb question but what's causing this? It didn't do this before I did the flush.

 

About what tempt does it read while idling? Without air flow it will get warmer a lot quicker but once your tstat opens up it will go back down. It's normal.

 

About half way, probably go further if I let it sit that long. Just weird it never did it before.

 

are the fans working? did you replace the tstat?

 

How can I test the fans? And no I didn't replace the tstat. Is there a way to test that also?

 

Fan Test

as for the stat you can pull it and put it in some water on the stove with a thermometer, or just replace it there like 5 bucks

 

Since it was OK before you flushed it, there is a good chance there is air in the system that needs to be purged out

 

i agree with pete prob has an air lock some of the newer cars will do this and it wont take much

 

what year and motor are we talkin about. if lt1 you need to bleed the system.

 

97, v6, 3.8