OK, few months back I noticed while driving that my temperature got up to about the 230 area and hung out there a bit but then fall back down to 186 and stayed there. So, to me that sounded just like a sticking thermostat and since a thermostat is relatively cheap I went ahead and changed it out. While I was changing it out I noticed that the coolant had gotten low on me without my noticing but didn't think much of it. Now, today I have the exact same problem so I go straight to the coolant level this time and it was back to being low once more and once I topped it off all problems went away. However, I can't seem to figure out where the coolant is going. I'm not seeing any signs of leakage on the exterior of the engine and the engine oil looks fine. I figure maybe the leak was on top of the piston and it was steaming it off and out the exhaust so I held a paper towel at the end of the exhaust pipe but it didn't catch anything. Does anyone have any ideas of where this coolant could be going? Any help is much appreciated.

 

could be the heads take off the valve covers

 

Read the TSB in the following thread.................... https://chevroletforum.com/forum/sil...9-5-3-a-54298/

 

Thanks MD that will definitely be my next course of action.