Hello. My 2012 chevy cruz started idling A rough sporadic idle while at a red light today. It has 61, 000 miles on it. When I got home and turned the car off i noticed the fan was running. Something that never happened after turning car off before . Upon entering the vehicle to go out Later, driving i noticed the engine light is now on. I began monitoring The coolant temperature as it went up and reached 214 - 217. When i returned back home in my driveway i turned the engine off and on the dashboard the temperature continued to go up and reach 220 . As I watched the temperature rise The fan kicked on again and the coolant temperature drop immediately. Can any tell me what the issue could be.

 

I had the same issue. The traction control lights also turned on eventually also. The issue is the idle they told me my valve cover gasket went bad causing a vacume leak. Changed the gasket all is well now. Could also be your pcv valve, see. That mentioned several times too. It's part of the valve cover. Your issue is a vacume leak per your post though. My c
2012 cruze always ran at 217-220 degrees so don't worry about that.

 

took car to the shop... YOU WERE ABSOLUTELY CORRECT!! THANK you so much.