i have an 07 ls 2.2 at 41,XXX miles my engine light appeared i ran a scan it said thermostat cleared code running fine 2 days later the coolant temp. guage in the dash said"---" but the engine light isnt on any more has anyone else had similar problems?

 

Sounds like low coolant level - the sensor is high and dry. Others on this forum have reported the "---" issue when the coolant is low.

 

sounds like you need to replace the thermostat. here is more info https://www.chevyhhr.net/forums/show...ght=thermostat

 

Heres some more info it talks about your gauge problem. https://www.chevyhhr.net/forums/show...=coolant+gauge

 

It's the thermostat - use the search function to get more information. The thermostat is jammed in the open position and the engine isnt warming up fast enough. So it will SOMETIMES trigger a code and ECL, and will also show --- in the digital temperature display. and you may find that the A/C will not work either.

 

Just had the same problem,its the thermostat.When that code appears the analog temp guage needle will be bottomed out and the DIC reads --- and like was stated above the a/c won't work either. The thermostat is covered under the 5 yr. 100,000 mile powertrain waranty. Bet you will find the rubber on the t-stat gone. I've had mechanics tell me that the dex cool coolant plays havoc on rubber(had one tell me the water pump seal probaly would be next) Gonna flush my cooling system and change coolant soon.

 

thanks for the responses im putting a new thermostat in tomoro

 

Here is a description of the process to replace it - your engine should be similar:
https://www.chevyhhr.net/forums/how-tutorial-library-21/how-save-%24350-00-thermostat-replacement-2-4l-p0128-24493/