I have a 2007 HHR with the 2.2 engine. Last August the A/C quit working. After trying the usual causes I found a thread that if the temp sensor was bad the AC wouldn't work. I replaced the temp sensor and all was good. Now the temp gauge is not working again, but intermittently. Could the temp sensor be bad already or is there another cause I should check?

 

Temp gauge in the dash cluster, they aren’t reliable, they don’t seem to want to move. Is the DIC coolant temperature registering? If so don’t worry about the temp gauge readings.

 

Most likely need a new T-stat. Only use ACDelco 131-158, or you will be sorry.

 

I didn't check this last time. When it was acting up last summer, neither the gauge or the DIC was working. I replaced the sensor and both worked, as well as the AC.

 

Now this thread is another one to look at. There are probably a 100 already..

When the computer is told that the engine is not warming up fast enough or not getting to operating temp at all; either because of a faulty sensor OR because of a faulty t-stat the temp gauge will flat line and the AC will not function.

Usually it is the t-stat. It can be intermittent depending on ambient temp and starting temp (like going to the 7-11 with no AC then getting back in and everything is ok.

The temp should be above 180F within about 5 minutes of start up and never fall below 180F. Most times this will be accompanied by a CEL and a code P0128.

 

Thank you Sir :)

 

Changed thermostat yesterday with proper ACDelco product. Temp gauge and DIC temp not registering now. What could be the problem?

 

Either a loose wire or an air bubble in the coolant, follow these directions

https://www.chevyhhr.net/forums/how-...-system-60614/

 

Which part number is the thermostat?