My check engine light has been coming on lately, and apparently the culprit is that my coolant temperature is too low. It fluctuates between about 155 and 170. I had the thermostat replaced at a dealership slightly over a year ago. Any ideas what would cause this? 2006 HHR LT1, 2.2l Auto.

 

Possibly another bad thermostat. Call the dealership and see if they will put another one in.

 

I'm on my third thermostat in a year and a half, so my bet is its your stat again....