I have the same issues happening....temp guage will pin, temp shows like 260 but car is not hot. been to the dealer, no code, nothing wrong. been doing this every couple of days for 6 months

 

This photo is looking down at the rear side of the coolant recovery tank. Look down at the rear side of the SS coolant recovery tank and on the rear side about 3 inches up from the bottom of the assembly there is a horizontal protrusion. The arrow in the photo points to this. It looks like a "rib" on the tank running left to right along the tanks rear side. The owners manual indicates this in a somewhat confusing manner. When the engine is cold the pink coolant should be at or slightly above the rib. The photo is from a 2010 SS with 5spd. Hopes this helps. There is a similar photo somewhere else on the site, but I put this here to make it easier. Hope your issue works itself out.

 

I had a similar issue happen to my 2008 SS. Back in July my temp shot up while sitting in traffic. As soon as I started to move the temp came down. I topped off the levels while the engine was cool and the issue went away. Here we are 3 months later and this morning sitting in traffic the car overheated. As long as I kept moving the Temp light would not come on. Any thoughts as to what might be going on. I'm to to top it off tonight and see what happens.

 

welcome to the site.....manos de lumbre Mine did the shoot up thing this summer, took it to the dealer and it checked out fine. but with the temp outside over 90 mine will run up to the 220's before coming down again. It never set off the light again so I chalked it up to its hot outside. That hardly ever happens here.

 

@manos de lumber, I have read your post about your situation with your HHR SS. I can understand how frustrating and concerning this must be. What is the highest that you have seen your temperature gauge at?

Michelle, Chevrolet Customer Service

 

@ CCS, it was up to about 260 on 11/2. I haven't done anything to it and it's been running at about 198. This morning in stop and go traffic, it got up to 220.