Yesterday driving home from work the AC stop working and the temperature gage stopped working. Then both started to work then stopped. finally the temp gage flashed red and went back to normal.
I got towed to my mechanic, he replaced the thermostat. drove it around and all was good. I picked it up and it did all the above again.

Any thoughts?

 

Did you check for OBD2 codes? Any thermostat except ACDelco 131-158 is asking for trouble.

 

That is the truth..

 

Yeah... Your mechanic didn't use the proper thermostat...

 

Or, could be intermittent temp sensor fault.

 

He didn’t burp the system either.
It would be odd to think he had the correct thermostat on his shelve.

 

Step one - Use proper thermostat
Step two - Burp the system and recheck
Step three - Find a person that knows what their doing and not Bubba.

 

We don't need to slam the mechanic. Aftermarket thermostats usually work just fine in other applications. HHRs are challenging to burp, and we don't know that it wasn't burped.

 

Driving back yesterday, all the same problems. The temperature ranged between 178 to 212.
I am going to take it back this afternoon and ask him if he knew about these comments.

My guy is not a Bubba (I know you were just kidding around). Old school mechanic, it will not leave his shop until he is sure it has been fixed. He may not have known about the above comments.

 

It should not get to 212F very much, only while sitting still for extended time. 178F is too low, the correct t-stat is 180F, the temp should always be above 180F after warming up.