Hello, my 06 z has run flawless since day 1. I decided to take off my Mrev and 5/16 spacer today and go back to stock, and i did the swap started the car, revd it, seemed good, backed it out of the garage and saw a puddle of antifreeze. i immediately popped the hood and noticed i didnt connect the rear coolant line that connects to the upper plenum. i connected it and added some water. drove the car around seemed, ok....stopped and the cooling fans went crazy and didnt turn off, smells like coolant too. alot. i back up go down the street, and the temp gauge flys up almost to the top....i picked up speed and turned down a side street, and it almost instantly dropped back down. i took the car back home and i am scratching my head. car has coolant, and doesnt seem to be leaking from anywhere else. any ideas? maybe needs a bleed? air in the system? please help!!!

 

Sounds like there's air in the system so you need to bleed. The trick to bleeding is to add coolant at a very slow rate - like you were peeing into the radiator.